(5 x^2+6 x +7)+(2 x^2+3 x +1) — (x^2+4 x -1) First, we need to take that subtraction sign and multiply it out. (5 x^2+6 x +7)+(2 x^2+3 x +1)+(- x^2 — 4 x +1) Now we can rearrange like values to make our lives easier. Since everything is now addition, the parenthesis are irrelevant. Make sure to be careful you don't lose track of any value! We expect there to be 3 of each type.5 x^2+2 x^2 — x^2+6 x +3 x — 4 x +7+1+1Now we simplify: 6 x^2+5 x +9I don't believe that can be factored any further.