Answer:
(B)21+3a
Step-by-step explanation:
An expression is said to be distributive when:
[tex](a+b)c=a \cdot c+b \cdot c[/tex]
Given the algebraic expression: (7 + a)3
Applying the distributive property
[tex](7 + a)3 = 7 \cdot 3+a \cdot 3\\=21+3a[/tex]
An equivalent expression is 21+3a.
The correct option is B
