Question

How do i work out 4x^2 - 9 ? Thanks!

Answer 1

what are you trying to do with it? Or what are you finding?

Answer 2

I need to factorise that expression to find values of X

Answer 3

oh... difference of squares... so... (2x+3)(2x-3)... then you set each = to 0.

Answer 4

so 2x+3=0
so 2x=-3
so x=-3/2

Answer 5

Did you just do (2x+3)^2 = 4x^2-9? How did you get the (2x-3)

Answer 6

Thanks!!!!

Answer 7

difference of squares. if you foil out (2x+3)^2 you get 4x^2+12x+9

Answer 8

youre welcome :D

Answer 9

Ps, how do i end this post/ say that the question has been solved, i dont wanna waster anyones time!

Answer 10

lol umm... look at the place in the left column of the page where u asked the question and press the close question button :)