Solve the quadratic equation 8x^2+6x-9

3 answers

factors of 8 ... 2 and 4

factors of -9 ... 3 and -3

2 * -3 = -6 ... 4 * 3 = 12 ... -6 + 12 = 6

(2x + 3)(4x - 3) = 8x^2+6x-9

this is the factoring of the EXPRESSION
... an equation has an equal sign (=) in it
i got till (4x-3)(2x+3) bt how do u get x=3/4 or -3/2
As R_scott pointed out to you, it should have been

8x^2+6x-9 = 0

which led to

(4x-3)(2x+3) = 0
Now, how can the multiplication of 2 numbers end up being zero???
Only if one of them is zero, but which one?
Well, it could have been either one, that is
4x-3 = 0 OR 2x+3 = 0
now just solve those two little equations

4x-3 = 0
4x = 3
x = 3/4 , same for the other one