Prepping for the GRE... It's been a while. Need a refresher on f(x)

Hey everyone!

I'm here because I'm getting ready to write the GRE, and I'm stumped, since it's been 9 years since I did any math. (Though I was good at it back in the day!)

"The function *f* is defined for all numbers *x* by *f(x) =* *x*^{2} + x. If *t* is a number such that *f (2t) = 30*, which two of the following could be the number *t*?

Indicate __two__ such numbers.

(Multiple choice: -5, -3, -1/2, 2, 5/2)"

Thanks in advance!

Re: Prepping for the GRE... It's been a while. Need a refresher on f(x)

Quote:

Originally Posted by

**jodester516** Hey everyone!

I'm here because I'm getting ready to write the GRE, and I'm stumped, since it's been 9 years since I did any math. (Though I was good at it back in the day!)

"The function *f* is defined for all numbers *x* by *f(x) =* *x*^{2} + x. If *t* is a number such that *f (2t) = 30*, which two of the following could be the number *t*?

You are given a formula for f(x) and asked about f(2t). Replace each "x" in the formula by "2t" and do the algebra.

Quote:

Indicate __two__ such numbers.

(Multiple choice: -5, -3, -1/2, 2, 5/2)"

Thanks in advance!

Re: Prepping for the GRE... It's been a while. Need a refresher on f(x)