х-y=4
x^2- y^2=40
x=4+y
(4+y)^2 - y^2 =40
16+y^2+8y-y^2=40
16+y^2+8y-y^2-40=0
8y-24=0
8y=24
y=24/8
y=3
x-y=4
x-3=4
x=7
х-y=4
x^2- y^2=40
x=4+y
(4+y)^2 - y^2 =40
16+y^2+8y-y^2=40
16+y^2+8y-y^2-40=0
8y-24=0
8y=24
y=24/8
y=3
x-y=4
x-3=4
x=7