Question

Solve. x2 + 15x = –56

a. x = 8 and x = 7
b. x = –8 and x = –7
c. x = –8 and x = 7
d. x = 8 and x = –7

I think its b, am i right?

Answer 1

x^2+15x+56
(x+8)(x+7)
x+8=0
-8 = -8
x=-8
x+7=0
-7 -7
x=-7
so
x=-8 and x=-7 so yes its b

Answer 2

thank u