What are the zeros of the function f (x) = x2+2x-35?

Use the quadratic formula:

x = [-b + - sq root (b^2 - 4ac) ] / 2a

a=1 b=2 c=-35

x = [-2 + - sq root (4 + 140) ] / 2

x = [-2 + - 12] / 2

x1 = (-2 + 12) / 2

x1 = 5

x2 = [-2 - 12] / 2

x2 = - 7