Question

Four expressions are shown below:


21x + 6
3(7x + 2)
18x + 9
3(6x + 3)

Which two expressions are equivalent to 3(6x + 2 + x)?
A and D
C and D
A and B
B and C

Answer 1

A and B would be correct 

A
3 * (6x + 2 + x) = 18x + 6 + 3x = 21x + 6

B
3(6x + 2 + x) = 3(7x+2)

Answer 2

A and B are equivalent to 3(6x+2+x).