Respuesta :

Jiggyfly
7(p+3q) cross multiply out, so now you have 7p+21q. This is the same thing as 7p+21q=0
Subtract 21q from both sides of the equation
7p=-21q
Divide by 7...
p=-3q
This is simplified as you can get it. 
I hope this helps you

7(p+3q)=(7)(p+3q)=(7)(p)+(7)(3q)=7p+21q