(20х+121)*18:402=9 (20х+121)*18=402*9 (20х+121)*18=3618 20х+121=3618:18 20х+121=201 20х=-201-121 20х=80 х=80:20 х=4 =
(20х+121)*18:402=9 (20х+121)*18=402*9 (20х+121)*18=3618 20х+121=3618:18 20х+121=201 20х=-201-121 20х=80 х=80:20 х=4 =