111k views
5 votes
(x + 2)^2 = 81
Solve by factoring , Show work and explain the steps you used to solve

User Publius
by
4.5k points

2 Answers

7 votes

Answer:

x = 7 , x = - 11

Explanation:


(x+ 2)^2 = 81\\\\(x+2) = √(81)\\\\(x+2) = \pm 9\\\\x + 2 = 9 \ , \ x + 2 = - 9\\\\x = 9 - 2 \ , \ x = - 9 - 2\\\\x = 7 \ , \ x = -11

User Charif DZ
by
4.9k points
4 votes

Answer:

x = 7, -11

Explanation:

(x + 2)^2 = 81

(7 + 2)^2 = 81 Take one value of x

9^2 = 81 Solve for the exponent

81 = 81 Final Answer

(x + 2)^2 = 81

(-11 + 2)^2 = 81 Take one value of x

9^2 = 81 Solve for the exponent

81 = 81

Understandings:

Understand how to solve for exponents

For example the ones that we used in this situation, in order to solve for an exponent, multiply the number by itself twice = 9 x 9 = 9^2 = 81

User Kientux
by
4.8k points