при x=3
118*3-56*3+35*3+27*3=372
4( 9+7x)+21=393
36+28x+21=393
57+28x=393
28x=393-57
28x=336
x=336/28
х=12
при x=3
118*3-56*3+35*3+27*3=372
4( 9+7x)+21=393
36+28x+21=393
57+28x=393
28x=393-57
28x=336
x=336/28
х=12