Answer:
x=−1 or x=1 or x=−7
Step-by-step explanation:
x3+7x2−x−7=0
Step 1: Factor left side of equation.
(x+1)(x−1)(x+7)=0
Step 2: Set factors equal to 0.
x+1=0 or x−1=0 or x+7=0
x=-7,-1,1