I seriously need help on this math problem. I have tried to work it out myself but the answer is not coming out right.

Select the approximate values of x that are solutions to f(x) = 0, where

f(x) = -8x2 + 3x + 7.

F(x) = Y = -8x^2 +3x +7 = 0

Use Quadratic Formula:

X = (-B +/- sqrt(B^2-4AC))/2A

X = (-3 +/- sqrt(9+224))/-16
X = (-3 +- sqrt233)/-16.
X = (-3 +- 15.26)/-16 = -0.767 and 1.14.