4×x=216
x=216/4
х=54
54000:x=3
x=54000:3
х=18000
x:12000=4
x=4*12000
х=48000
x-415=326
x=326+415
х=741
990-x=176
-x=176-990
-x=-814
х=814
4×x=216
x=216/4
х=54
54000:x=3
x=54000:3
х=18000
x:12000=4
x=4*12000
х=48000
x-415=326
x=326+415
х=741
990-x=176
-x=176-990
-x=-814
х=814