5−8c 2 =−75

Sure, here is the step-by-step solution for the equation:

1. Rewrite the equation: 5 - 8c^2 = -75
2. Subtract 5 from both sides: -8c^2 = -80
3. Divide both sides by -8: c^2 = 10
4. Take the square root of both sides: c = sqrt(10) or c = -sqrt(10)

So, the solutions for the equation are c = sqrt(10) and c = -sqrt(10).