Respuesta :

drwhoowls
-3(b - 7)

-3*b = -3b

-3*7 = -21

-3b - 21
texaschic101
-3(b - 7)...distribute thru the parenthesis...that means multiply 3 by everything in the parenthesis to get rid of the parenthesis

(-3 * b) - (-3 * 7) = -3b - (-21) = -3b + 21 <==