Respuesta :

7b + 4 (-b +3)
= 7b +4*(-b)+ 4*3
= 7b -4b+ 12
= 3b + 12

The final answer is 3b+12.

Hope this helps~
7b+4(-b+3)=7b-4b+12=3b+12=3(b+4)
Have a nice day!! ^^