Question

Please help me with a explanation

Answer 1

Answer:

x = -3   or   x = 3

Step-by-step explanation:

Subtract 9 from both sides.

x^2 - 9 = 0

Factor the left side. There is no common factor of the terms. It is a binomial which is the difference of two squares, so it factors into the product of a sum and a difference.

(x + 3)(x - 3) = 0

Set each factor equal to zero.

x + 3 = 0   or   x - 3 = 0

Solve each equation.

x = -3   or   x = 3