Question 144725
1/2x(x+20)=78
2[ 1/2x(x+20)=78]
x(x+20)=156
x^2 + 20x = 156
x^2 + 20x - 156 = 0
(x - 6)(x + 26) = 0
x - 6 = 0
x = 6
x + 26 = 0
x = -26
x = 6 or -26