Решите уравнение:

X· (X-10) = 56

X· (X+16) = 80

X (x-10) = 56

x²-10x-56=0

D=10²+4*56=100+224=324

x (1) = (10+18) / 2=28/2=16

x (2) = (10-18) = - 8/4=-4

x (x+16) = 80

x²+16x-80=0

D=16²+4*80=256+320=576

x (1) = (-16+24) / 2=8/2=4

x (2) = (-16-24) / 2=-40/2=-20