Verified answer

p₁(x)+p₂(x)=(x²+2x-3)+(2x²-4x-5)=x²+2x-3+2x²-4x-5=3x²-2x-8

p₁(x)-p₂(x)=(x²+2x-3)-(2x²-4x-5)=x²+2x-3-2x²+4x+5=-x²+6x+2

(4x-9)-(2x-3)-x²=5-(x+x²)

4x-9-2x+3-x²=5-x-x²

2x-6=5-x

3x=11

x=3 целых 2/3