Решим каждое уравнение по шагам:
а) x + 125 = 230 + 25
x + 125 = 255
x = 255 - 125
x = 130
б) a – 37 = 54
a = 54 + 37
a = 91
в) b × 36 = 72 - 16
b × 36 = 56
$$b = \frac{56}{36} = \frac{14}{9}$$
$$b = \frac{14}{9}$$
г) 1836 : (x – 26) = 18
x – 26 = 1836 : 18
x – 26 = 102
x = 102 + 26
x = 128