Решите уравнение 13+10t=163,9y-54=162, 181-8r=45

13+10t=163
10t = 163 - 13
10t = 150
t= 150 : 10
t= 15

9y-54=162
9y = 162 + 54
9y = 216
y = 216 : 9
у = 24

181-8r=45
-8r = 45 - 181
-8r = -136
r = -136 : (-8)
r = 17

13+10t=163.
10t = 163-13.
10t = 150.
t = 150:10.
t = 15.

9y-54 = 162.
9y = 162+54
9y = 216.
y = 216:9.
y = 24.

181-8r = 45
-8r = 45-181.
-8r = -136
r = -136: (-8).
r = 17. Не так? Здесь нет никаких скобок?