Respuesta :

  -7x + 28y + 63z 
let me know if you dont know how I did this
 
emobri99
take -7 and multiply it by everything inside the parenthesis and go from there.
-7x+28y+63z
you have to add because the outcomes are positive.
I will let you handle the rest since your in college.
you got this your smart!!!!