Question 181889
4x^2+11x=2x^2-15
2x^2+11x+15=0
(2x+5)(x+3)=0
2x=5  <<--should be 2x=-5
x=5/2 <<--should be x=-5/2
x=3   <<--should be x=-3
.
For example, you're setting each term to zero:
(2x+5)=0
subtracting 5 from each side:
2x = -5
dividing both sides by 2:
x = -5/2