Проверка:
a + 10 = 90a = 90 - 10a = 80
a : 20x = 0 : 20x80 : 20x = 0 : 20x4x = 0x = 0/4x = 0/2x = 2
Таким образом, a = 80 и x = 2.
Проверка:
a + 10 = 90
a = 90 - 10
a = 80
a : 20x = 0 : 20x
80 : 20x = 0 : 20x
4x = 0
x = 0/4
x = 0/2
x = 2
Таким образом, a = 80 и x = 2.