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

4096 bacteria

step-by-step explanation:

arrange the equations with like terms in columns.

analyze the coefficients of x or y.

add the equations and solve for the remaining variable.

substitute the value into either equation and solve.

check the solution.

step-by-step explanation: