Solve the equation by factoring. 15=8x^2-14x

8x^2 - 14x - 15 = 0

8 * - 15 = - 120 so we want 2 numbers which when added give us - 14

-20 and 6 look good, so we can write:-

8x^2 - 20x + 6x - 15 = 0

4x (2x - 5) + 3 (2x - 5) = 0

2x-5 is common so we have:-

(4x + 3) (2x - 5) = 0

4x + 3 = 0 or 2x - 5 = 0

solution is - 3/4 and 5/2

The solution is the result of 2x-5 = 0 and 4x+3 = 0.

x=5/2, - 3/4 (That's negative three fourths).