Answer:
B. x = -5 +/- √30.
Step-by-step explanation:
2x^2 + 20x = 10
2(x^2 + 10x) = 10
2[ (x + 5)^2 - 25 ] =10
2(x + 5)^2 - 50 = 10
2(x + 5)^2 = 60
(x + 5)^2 = 30
x + 5 = +/- √30
x = -5 +/- √30.
