Question 12085
(12a-3b+5c)-5(-5a+4b-6c) 
12a-3b+5c+(-5)(-51)+(-5)(4b)+(-5)(-6c)
12a-3b+5c+25a-20b+30c           <--add up all the like terms
(12a+25a)-3b-20b+(5c+30c)
37a-23b+35c