A i need help again. Which two expressions are equivalent?

A. 7(3 + x) and 7∙ 3 + 3 ∙ x
B. 7 + 3 + x and (7 + 3) + x
C. 7 ∙ x ∙ 3 and 7(x + 3)
D. 7 ÷ (3 – x) and 7 ÷ (x – 3)

B

Step-by-step explanation:

A. these simply to 21 + 7x and 21 + 3x

this one is incorrect because the 7x and 3x are different

B. these simplify to 10 + x and 10 + x

this is the correct one since they are exactly the same

C. these simplify to 21x and 7x + 21

these two are not the same because one expression has only a number with a variable but the other one has a number with a variable and another number

D. these simplify to    and  

in subtraction, the order of the 3 and the x matters, so the equations are not the sameexample: 6 - 4 = 2 but 4 - 6 = -2