How do you check to make sure a division equation is correct?

If f(x)=x^3 and g(x)=2x+7 when g(x)=-5

Ray ce is the angle bisector of zacd, which statement about the figure must be true? mzecd-mzecb mzace « 4mzacd zace - zdcb zecd zacd save and exit

How do you solving the solution of each system using elimination?