Question

Which expression is equivalent to 21x + 9 - 3x? A. 9(2x - 1) B. 9(x + 1) C. 9(2x + 1) D. 18(x + 1) ​

Answer 1

Answer: A. 9(2x - 1)

Explanation:

combine like terms

21x+9-3x

21x-3x

18x+9

Factor the expression

factor out 9 from the expression

you get 9(2x - 1)

Answer 2

Answer: C

Explanation:

21x+9-3x = 18x + 9

If you factor out the 9, you would be left with

9 (2x+1)