7*(x+14)-9*(x-2)=12x+32
7х+98-9х+18=12х+32
7х-9х-12х=32-98-18
-14х=-84
х=-84:(-14)
х=6
проверка:
7*(6+14)-9*(6-2)=12*6+32
104=104
-14х=-98-18+32
-14х=-8
7*(x+14)-9*(x-2)=12x+32
7х+98-9х+18=12х+32
7х-9х-12х=32-98-18
-14х=-84
х=-84:(-14)
х=6
проверка:
7*(6+14)-9*(6-2)=12*6+32
104=104
7*(x+14)-9*(x-2)=12x+32
7х+98-9х+18=12х+32
-14х=-98-18+32
-14х=-8
х=6