Studying for the GRE

[ladyskydiver 0]

ARG!!!! Why oh why do they need to torture you with this stuff?

Ok...someone refresh my memory on the steps to take to solve these kinds of problems (it's been ages since I've dealt with some of this stuff).

(Sorry about the lack of a square root sign for the first 2)

a) 5 square root 3 + square root 27 = ??? And the answer needs to keep the square root in it.

b) square root 300 divided by square root 12 = ???

c) 3x squared + 10x - 8 = 0

d) 15x-18-2y = -3x+y
10x+7y+20 = 4x+2

Thanks!

Life is short! Break the rules! Forgive quickly! Kiss slowly! Love truly, Laugh uncontrollably. And never regret anything that made you smile.

[lawrocket 3]

Dang. I'm glad I stuck with the LSAT.

My wife is hotter than your wife.

[yamtx73 0]

dam'n.. I haven't done that kind of math in 30 years.... hell if I can remember how it's done....

The only naturals in this sport shit thru feathers...

[freefalle 0]

do you mean 5 to the third + 27 squared?

[Icon134 0]

Quote

a) 5 square root 3 + square root 27 = ??? And the answer needs to keep the square root in it.

Factor the SQRT(27) = SQRT(3)*SQRT(9) = 3 SQRT(3)

Then 5 SQRT(3) + 3 SQRT (3) = (5+3) SQRT (3)

=> ANS: 8 SQRT(3)

the second one is similar to the first.

Livin' on the Edge... sleeping with my rigger's wife...

[MakeItHappen 15]

This is basic algebra. I'm not going to do your homework, but here are some hints.

sqrt(ab) = sqrt(a) * sqrt(b)
27 = 3*9
300 = 3*100
12 = 3*4

The quadratic formula would come in handy. That's a well know formula.

Solve for one variable and substitute in the other equation.

For the verbal part try this.

.

.
Make It Happen
Parachute History
DiveMaker

[ladyskydiver 0]

Quote

Quote

a) 5 square root 3 + square root 27 = ??? And the answer needs to keep the square root in it.

Factor the SQRT(27) = SQRT(3)*SQRT(9) = 3 SQRT(3)

Then 5 SQRT(3) + 3 SQRT (3) = (5+3) SQRT (3)

=> ANS: 8 SQRT(3)

the second one is similar to the first.

Thanks! Following the logic behind it now. )

Life is short! Break the rules! Forgive quickly! Kiss slowly! Love truly, Laugh uncontrollably. And never regret anything that made you smile.

[ladyskydiver 0]

Quote

do you mean 5 to the third + 27 squared?

Nope...Icon did it best with the way he did the question....

5 SQRT(3) + SQRT(27) = 8 SQRT(3)

Life is short! Break the rules! Forgive quickly! Kiss slowly! Love truly, Laugh uncontrollably. And never regret anything that made you smile.

[Icon134 0]

You can... but you need to know that SQRT(3) is approximately 1.73...

and of course then it is only an approximate answer.

Livin' on the Edge... sleeping with my rigger's wife...

[NWFlyer 2]

Math is hard. Let's go to the mall!

I feel for you. I had to relearn some of the math stuff when I took the GMAT a couple years out of college (and well after I'd taken my last math class.)

Good luck!

"There is only one basic human right, the right to do as you damn well please. And with it comes the only basic human duty, the duty to take the consequences." -P.J. O'Rourke

[Icon134 0]

Quote

c) 3x squared + 10x - 8 = 0

the quadradic formula is an excelent way to solve for x in this problem.

using it x = (-b+-SQRT(b^2-4ac))/2a

Quad Eqn

where ax^2 + bx + c = 0

edited to "fix" the parenthesis in my quadradic Eqn...

Livin' on the Edge... sleeping with my rigger's wife...

[Icon134 0]

Quote

d)
15x-18-2y = -3x+y
10x+7y+20 = 4x+2

This type of problem can be done 2 ways.

you can solve for x in terms of y in one of the eqns then put it into the second equation.

the other way is to put all of the variables on one side and see if you can come up with a common factor to eliminate one of the variables on in one of the equations... see below...

-3(6x + 7y) = -3(-18)
-18x + 21y = 54 (eqn 2)

18x - 3y = 18 (eqn 1)

add the 2 together...

0x + 18y = 72

y = 72/18 = 4

then put the value for y back into one of the above equations and solve for x

18x - (3)(4) = 18

18x - 12 = 18

18x = 30

x = 30/18

Of course this all assumes I didn't make any calculation errors.

Scott

Livin' on the Edge... sleeping with my rigger's wife...

[ladyskydiver 0]

<-- Put's Scott on Emergency PM list

Thank you! It's appreciated. It has been...well, let's just say "years" since I've had to do these kinds of problems. I appreciate the help in refreshing my memory of the steps involved in solving them.

Life is short! Break the rules! Forgive quickly! Kiss slowly! Love truly, Laugh uncontrollably. And never regret anything that made you smile.

[ladyskydiver 0]

Quote

Math is hard. Let's go to the mall!

I feel for you. I had to relearn some of the math stuff when I took the GMAT a couple years out of college (and well after I'd taken my last math class.)

Good luck!

I'm a barbie girl...in a barbie world...

Yikes! errr...umm...someone took over my computer. I don't know the lyrics to Aqua's song at all.


Thanks! I've got an upcoming "Math for Geologists" class ( don't get the name of it, but...) in January - 5 classes worth - but it's covering calc 221/222/differential equations. The "simple" stuff...well...I'm glad there are people who remember it and can refresh my memory on the steps to solve them.

Life is short! Break the rules! Forgive quickly! Kiss slowly! Love truly, Laugh uncontrollably. And never regret anything that made you smile.

[waltappel 1]

Quote

ARG!!!! Why oh why do they need to torture you with this stuff?

Because they can.

You've already gotten some great answers, but I'll try to add in a little more detail here.

Quote

a) 5 square root 3 + square root 27 = ??? And the answer needs to keep the square root in it.

What is important here (if any of this can be considered "important") is NOT the square roots. They just put that in to screw with your mind. Conceptually, let's simplify it a bit.

square root 3 = x
square root 27 = y

5 x + y = ???

In algebra, there is a thing that they preach as absolute truth when it comes to solving equations with variables, and that is "If you have 'n' (some number) of variables, then you need 'n' independent equations to solve them."

In this case you have one equation. You really don't have any variables, but you have exponential expressions and they have some special rules, so it's kind of like you have two variables, square root 3 and square root 27, so you need to reduce the number of "variables to one as you seek the truth. (Yes, I'm being sarcastic--I hate this stuff just as much as you do.)

There are things the algebra people preach about exponents, like for the "root" expressions, the exponent takes the form of a fraction--one over whatever the root number is. In this case the exponent is 1/2.

So, I'm going to change notation here for my convenience. "**" means "to the power of", so "X**2" means "X to the power of 2" or "X squared".

So we have: 5(3**1/2) + 27**1/2 = ???

So onward and downward. What we are going to do is try and put the equation into the form of (some number) times (3**1/2) plus (another number) times (3**1/2) equals our magical answer. The reason why will make a little more sense later.

As someone pointed out earlier, you do it by factoring. We'll get to that in a minute.

Exponents being designed to screw with your head and all, here's the trick to factoring exponents. I'll use square roots in this case, but it is quite easy to generalize.

(X times Y)**1/2 = (X**1/2) times (Y**1/2)

Here's an example:
square root of 10,000 = ???
(100 * 100)**1/2 = ???
100**1/2 * 100**1/2 = ??

Since 10 = 100**1/2, the answer is 10 times 10 or 100.

If someone asks you, "Hey ladyskydiver, what, oh pray tell what is the square root of 10,000.

"Simple, you fucktard", you say. "The square root of 10,000 is the same as the square root of 100 times 100, which is the same as the square root of 10 squared times 10 squared, which is the same as the square root of ten squared times the square root of ten squared which equals 10 times 10 or 100. You may pay me in jump tickets."

They will be in awe!!!

So, back to the problem at hand. Applying that to this problem,

(27)**1/2 = (9 times 3)**1/2 = (9)**1/2 times (3)**1/2

That reduces to 3 times 3**1/2.

So........
(5 times 3**1/2) plus (3 times 3**1/2) = ??

Another thing those evil algebra people (and I suspect "Kallend" is one) preach is that you can add expressions having the same base and the same exponent. Here's an example: 5(X**2 ) + 3(X**2) = 8 (X**2).

So.......
8 times 3**1/2 = ???

There's your answer.

If you want similar long-winded explanations to the other problems, let me know.

Walt

[MakeItHappen 15]

Quote

If you want similar long-winded explanations to the other problems, let me know.

Explanations like that explain why people get turned off by algebra.

There are much simpler concepts behind algebra.
Operators can be associative, commutative or distributive.
Operators have orders of precedence.
The number one can be expressed in a number of ways.

BTW, Icon's quadratic formula is incorrect. (((((((Just matching parens would show that.))))

The last math class I had was circa 1978.

Education is a funny thing. You pay a lot of money and hope you 'get cheated' either by cancelled classes or not having to learn something.

Anyway, anyone entering Grad school ought to know basic algebra, no matter what field they are going into.

.

.
Make It Happen
Parachute History
DiveMaker

[waltappel 1]

Quote

Quote

If you want similar long-winded explanations to the other problems, let me know.

Explanations like that explain why people get turned off by algebra.

No, algebra does a fine job of turning people off all by itself. So does trig. So does calculus. So does vector calculus. So does differential equations.

Quote

Anyway, anyone entering Grad school ought to know basic algebra, no matter what field they are going into.

.

You're kidding, right? That's like saying everyone ought to know art history or some other niche thing.

Walt

[MakeItHappen 15]

Quote

No, algebra does a fine job of turning people off all by itself. So does trig. So does calculus. So does vector calculus. So does differential equations.

Well, you need better teachers because all of those subjects can be taught in a manner to turn on the most disinterested student. I've had some REALLY disinterested students too. I've had horrible teachers and excellent teachers.

Quote

You're kidding, right? That's like saying everyone ought to know art history or some other niche thing.

You know, art history does not really transcend disciplines as basic algebra does. Even art history depends on algebra. You want to buy this $23,000 piece for 15% off of the price, what would you have to pay?

.

.
Make It Happen
Parachute History
DiveMaker

[kallend 2,145]

Quote

Quote

Math is hard. Let's go to the mall!

I feel for you. I had to relearn some of the math stuff when I took the GMAT a couple years out of college (and well after I'd taken my last math class.)

Good luck!

I'm a barbie girl...in a barbie world...

Yikes! errr...umm...someone took over my computer. I don't know the lyrics to Aqua's song at all.


Thanks! I've got an upcoming "Math for Geologists" class ( don't get the name of it, but...) in January - 5 classes worth - but it's covering calc 221/222/differential equations. The "simple" stuff...well...I'm glad there are people who remember it and can refresh my memory on the steps to solve them.

I once co-authored a research paper in a geology journal, and the mathematics content was pretty serious: integral equations, linear algebra (tensor transformations), group theory and spherical trig for starters.

...

The only sure way to survive a canopy collision is not to have one.

[thegreekone 0]

yer cookin with gas now, hon!


*relieved she has others to go to for math stuff*

[waltappel 1]

Quote

Quote

No, algebra does a fine job of turning people off all by itself. So does trig. So does calculus. So does vector calculus. So does differential equations.

Well, you need better teachers because all of those subjects can be taught in a manner to turn on the most disinterested student. I've had some REALLY disinterested students too. I've had horrible teachers and excellent teachers.

Hehehehehehehehe!!!

Quote

You're kidding, right? That's like saying everyone ought to know art history or some other niche thing.

You know, art history does not really transcend disciplines as basic algebra does. Even art history depends on algebra. You want to buy this $23,000 piece for 15% off of the price, what would you have to pay?
.

[ladyskydiver 0]

Quote

Anyway, anyone entering Grad school ought to know basic algebra, no matter what field they are going into.

Let me explain something. It's been years since I've done the simpler math. I've done business calc, trig, etc. and will be taking the aforetomentioned math class in 1 week.

A refresher is all that I'm needing. I get the concepts once re-reminded of them. And the long explanations are nice. I love understanding the whole logic behind the theory - Thanks, Walt!!!

Quote

Education is a funny thing. You pay a lot of money and hope you 'get cheated' either by cancelled classes or not having to learn something.

You are not talking about me. I love class and learning. So, sorry that my post is something that seems to have bothered you by me asking for a refresher.

Life is short! Break the rules! Forgive quickly! Kiss slowly! Love truly, Laugh uncontrollably. And never regret anything that made you smile.

[waltappel 1]

Quote

Quote

Anyway, anyone entering Grad school ought to know basic algebra, no matter what field they are going into.

Let me explain something. It's been years since I've done the simpler math. I've done business calc, trig, etc. and will be taking the aforetomentioned math class in 1 week.

A refresher is all that I'm needing. I get the concepts once re-reminded of them. And the long explanations are nice. I love understanding the whole logic behind the theory - Thanks, Walt!!!

You're very welcome.

[See there, MakeItHappen?!!!! Nyah, Nyah!!!!!]


Walt

p.s. Once again, MakeItHappen--Nyah, Nyah!!!!!]

[Icon134 0]

Quote

BTW, Icon's quadratic formula is incorrect. (((((((Just matching parens would show that.))))

That's why I included the link...

btw: I've since gone back up to fix it...

Livin' on the Edge... sleeping with my rigger's wife...

[waltappel 1]

Quote

I once co-authored a research paper in a geology journal, and the mathematics content was pretty serious: integral equations, linear algebra (tensor transformations), group theory and spherical trig for starters.

Gee, one of your friends, flyangel2, thinks you're hilarious. This post gives me a headache!!!

Walt