Where does the section of the bridge meet ground level? Solve 0 = - x2 + 10x - 8

In can be less mental effort if the equation is multiplied by - 1 first.

... x^2 - 10x + 8 = 0

... x^2 - 10x + 25 + 8 - 25 = 0

... (x - 5) ^2 = 17

... x - 5 = ±√17

... x = 5 ±√17

The values of x that satisfy the given equation are

... x = 5 - √17 ≈ 0.877

... x = 5 + √17 ≈ 9.123