Question

Your answer 1) A teacher asked the class to solve the equation 3(x + 2) = 21. Robert wrote 3x + 6 = 21 as his first step. Which property did he use? associative property

Answer 1

1) A teacher asked the class to solve the equation 3(x + 2) = 21. Robert wrote 3x + 6 = 21 as his first step. Which property did he use? associative property​

The property used was Distributive property

so

3(x + 2) = 21

3x+3*2=21

3x+6=21

answer is

Distributive property

If we have

3(x+2)

applying distributive property means, that you multiply the number outside the parenthesis by each number inside the parenthesis

so

3*x+3*2

3x+6