Explanation:
Use the quadratic formula to find the solutions.
−b±√b2−4(ac)2a-b±b2-4(ac)2a
Substitute the values a=9a=9, b=0b=0, and c=−81c=-81 into the quadratic formula and solve for xx.
x=±3x=±3
The final answer is the combination of both solutions.
x=3,−3x=3,-3