Use the Quadratic Formula to solve for the zeros of the following quadratic polynomials: (Enter the zeros in a comma-separated list; use $i$ for $\sqrt{-1}$.)

(a) $8 x^2 + 4 x + 8 = 0$
Zeros:

(b) $-7 x^2 + 5 x - 2 = 0$
Zeros:

Hint: