Answer:
x = 9 and -9
Step-by-step explanation:
[tex]x^{2}[/tex] -81 = x add 81 to both sides of the equation
[tex]x^{2}[/tex] = 81 What number times itself equals 81? 9 and -9
Answer: + 9
Step-by-step explanation: add 81 to both sides to isolate x^2. we get x^2= 81. take the square root of both sides. the square root of x^2 is x and square root of 81 is 9 or -9. so x = 9 and -9.
