Solve and Choice

Question

if 4x^2 = 13, then what is the value of (2x - 3)(2x - 3)?

 

a. 4

b. 22 - 6 times square root of 3

c. square root of 3 -9

d. -22

Answer 1

I'm guessing, but I think that you meant (2x-3)(2x+3).

 

The reason I say that is because when you multiply these out, you get 4x² - 9.

 

You can then look at your original equation   4x²      = 13

and subtract 9 from both sides                           -9      -9

 

to get 4x² -9 = 4.

 

Since that is one of your choices, I am assuming that's what you meant.

 

Hope this helped.