Respuesta :

-3(b - 7)

Multiply -3 into the parenthesis.

= -3b + 21.
MathWz
Multiply -3 to each term in the parentheses:
-3(b)= -3b
-3(-7)= 21
These are not like terms, so write them as an expression:
-3b + 21 or 21 - 3b