4. Solve. x² – 81 = 0 (1 point) 0 –9 –9, 9 9

x^2 - 81 = 0. Add 81 to each side.

x^2 = 81. Take the square root of each side.

x = 9, -9

–9, 9

Step-by-step explanation:

x² – 81 = 0

Add 81 to each side

x² – 81+81 = 0+81

x^2 = 81

Take the square root of each side

sqrt(x^2) = ± sqrt(81)

x = ± 9

e

step-by-step explanation:

an equation by definition has to have two or more variables (x and 2 in this case)