12х + 24 = 15х - 18
12х - 15х = -18 - 24
-3х = -42
х= -42 : (-3)
х = 14
12*14 + 24 = 15 * 14 - 18
192 = 192
12х + 24 = 15х - 18
12х - 15х = -18 - 24
-3х = -42
х= -42 : (-3)
х = 14
12*14 + 24 = 15 * 14 - 18
192 = 192