normally, you would do whatever is inside of the parenthesees first then do the rest but we cant get any further so we remove the parenthasees by distrubtion
7a+6b-4(3a-3b)
-4(3a-3b)
a(b+c)=(ab)+(ac)
-4(3a-3b)=-12a-(-12b)
7a+6b-12a+12b
7a-12a+6b+12b
-5a+18b
that's the asnwer
