Нижняя- x
(x-15)/3=(120-x)+15/1
(x-15)*1=(120-x)+15))*3
x-15=360-3x+45
x+3x=405+15
4x=420:4
x=105(кн)-нижняя
120-105=15
Получаем систему уравнений
![\left \{ {{x - y = 4} \atop { x^{2} - y^{2} = 32}} \right.\left \{ {{x - y = 4} \atop {(x-y)(x+y) = 32}} \right. \left \{ {{x - y = 4} \atop {4(x+y) = 32}} \right.\left \{ {{x - y = 4} \atop {x+y = 8}} \right.\left \{ {{x = 4+y} \atop {x+y = 8}} \right. \left \{ {{x = 4+y} \atop {4+y+y = 8}} \right.](https://tex.z-dn.net/?f=%5Cleft+%5C%7B+%7B%7Bx+-+y+%3D+4%7D+%5Catop+%7B+x%5E%7B2%7D+-+y%5E%7B2%7D+%3D+32%7D%7D+%5Cright.%5Cleft+%5C%7B+%7B%7Bx+-+y+%3D+4%7D+%5Catop+%7B%28x-y%29%28x%2By%29+%3D+32%7D%7D+%5Cright.%0A%5Cleft+%5C%7B+%7B%7Bx+-+y+%3D+4%7D+%5Catop+%7B4%28x%2By%29+%3D+32%7D%7D+%5Cright.%5Cleft+%5C%7B+%7B%7Bx+-+y+%3D+4%7D+%5Catop+%7Bx%2By+%3D+8%7D%7D+%5Cright.%5Cleft+%5C%7B+%7B%7Bx+%3D+4%2By%7D+%5Catop+%7Bx%2By+%3D+8%7D%7D+%5Cright.+%5Cleft+%5C%7B+%7B%7Bx+%3D+4%2By%7D+%5Catop+%7B4%2By%2By+%3D+8%7D%7D+%5Cright.)
![\left \{ {{x = 4+y} \atop {2y = 4}} \right. \left \{ {{x = 4+y} \atop {y = 2}} \right.](https://tex.z-dn.net/?f=%5Cleft+%5C%7B+%7B%7Bx+%3D+4%2By%7D+%5Catop+%7B2y+%3D+4%7D%7D+%5Cright.%0A%5Cleft+%5C%7B+%7B%7Bx+%3D+4%2By%7D+%5Catop+%7By+%3D+2%7D%7D+%5Cright.)
y = 2, значит x = 2+4 = 6
Ответ: y = 2, x = 6
7²=49
8²=64
49<53<64
7<√53<8
Сейчас решу, но половину максимум