Решите уравнение 4)у-12\31=5 5)2z+32\17=10 6)81\2х+3=9

4) 
y - 12 = 5 *31
y = 155 + 12
y = 167

5)
2z + 32 = 170
2z = 170 - 32
z = 138 / 2
z = 69

6)
81 / 9 = 2x + 3
2x = 9 - 3
x = 6 / 2
x = 3