Mostly collect like terms use associative property which is (a+b)+c=a+(b+c) and remember that: you just use a general rule x+x=2x x^2+x^2=2x^2 3xy4xy=7xy 3x+4x^2=3x+4x^2 you can only add like terms( like terms are terms that are same name like x or y are differnt, and like terms have same power exg x^2 and x^3 and x^1/2 and such
so first one
3b+11c-4c-c since they are all c except for the first one term, just assign a number for each so it simplifies to c times(11-1)+b(3-4)=c(10-1b=10c-b or
you just use a general rule x+x=2x x^2+x^2=2x^2 3xy4xy=7xy 3x+4x^2=3x+4x^2
second one9a-1+8c-8a+c group like terms (9a-8a)+(8c+c)-1=(a)+(9c)-1=a+9c-1
12c+5a+7-13c+4a group like terms(12c-13c)+(5a+4a)+7 add like terms -c+9a+7 the solution is 9a-c+7
-15-6c+3b-6c+9-2b group like terms (-15+9)+(-6c-6c)+(3b-2b) -6+(-12c)+b=b-6-12c
