Question

(x+5)^2+(x-2)^2+(x-7)(x+7)=11x+80

Answer 1

x²+10x+25+x²-4x+4+x²-49=11x+80
3x²+6x-20-11x+80=0
3x²-5x-100=0
d=25+1200=1225
x1=

Answer 2

x1=(5+35)/6=40/6=6 целю 2/3

Answer 3

x2=(5-35)/6=-30/6=-5