Пошаговое объяснение:
2x - 15 = 13
2x = 13 + 15
2x = 28
x = 28 : 2
x = 14
7y - 25 = 45
7y = 45 + 25
7y = 70
y = 70 : 7
y = 10
130 - 4x = 70
4x = 130 - 70
4x = 60
x = 60 : 4
x = 15
