Answer:
A and C
Step-by-step explanation:
Given
4d + 6 + 2d ← collect like terms
= 6d + 6
Comparing the following
A
2(3d + 3) ← distribute parenthesis by 2
= 6d + 6
B
6(d + 6) ← distribute parenthesis by 6
= 6d + 36 ≠ 6d + 6
C
(3d + 3) + (3d + 3) ← remove parenthesis
= 3d + 3 + 3d + 3 ← collect like terms
= 6d + 6
Thus A and C are equivalent to the original expression
