13. The perimeter of a triangle is 7p²-5p+11 and two of its sides are p2 +2p-1 and 3p2 -p +3. Find the third side of the triangle.

What the proper work

I'll do the first one for you. it isn't very hard at all.on number one, you have (50 × 3), which equals 150, and (3 × 3), which equals 9. after you establish that, you add 150 and 9 together. so, (150 + 9) equals 159.this means that 53 × 3 = 159.