решите уравнение:
y*28=756: х:17=221: (х-18)*17=408: 232:х+21=50

y*28=756
y=756:28
y=27
x:17=221
x=221*17
x=3757
(x-18)*17=408
x-18=408:17
x-18=24
x=24+18
x=42
232:x+21=50
232:x=50-21
232:x=29
x=232:29
x=8