1)
4 - 7x +5 - 5x = 60 - 6x - 3
9 - 12x = 57 - 6x
-12x + 6x = 57 - 9
-6x = 48
x = -48 : 6
x = -8
2)
10 - y + 6y + 16 = 3y + 18
26 + 5y = 3y + 18
5y - 3y = 18 - 26
2y = -8
y = -8 : 2
y = -4
3)
12x + 20 + 45x - 25 = 120 + 30x + 10
57x - 5 = 130 + 30x
57x - 30x = 130 + 5
27x = 135
x= 135 : 27
x = 5
4)
5 - 9x - 6 - 10x = 20 - 12x
-1 - 19x = 20 - 12x
-19x + 12x = 20 + 1
-7x = 21
x = -21 : 7
x = -3