Suppose f(x) = x square -8x +20 find x such that f(x) =24

A.) x={3+- 3 square root of 2}
B.) x= {-4 +- 2 square root of 5}
C.) x= {-3+- 3 square root of 2}
D.) x={ 4+- 2 square root of 5}