Solve. Round to the nearest one decimal.

7x^3 + 5x^2 - 5x - 3

I will assume you meant solve

7x^3 + 5x^2 - 5x - 3 = 0

On the second try, I found x = -1 to be a solution
so (x+1) is a factor.
Using synthetic division I found
7x^3 + 5x^2 - 5x - 3 = (x+1)(7x^2 - 2x -3)

so solving 7x^2 - 2x - 3 = 0 using the formula gave me
x = (2 ± √88)/14
= (-1 ± √22)/7

Use your calculator to evaluate to the nearest decimal