8x^3 + 1 = 0
8x^3 = -1 <----------- Step 1: Subtract 1 from both sides.
x^3 = -1/8 <----------- Step 2: Divide both sides by 8.
x = ∛(-1/8) <----------- Step 3: Cube root both sides
x = -0.5 <----------- This is the final answer when you plug the last step into the calculator