a) (a - 84) : 2 = 388
a - 84 = 388 x 2 = 776
a = 776 + 84 = 860
b) (a x 5 + 5) - 28 = 12
a x 5 + 5 = 12 + 28 = 40
a x 5 = 40 - 5 = 35
a = 7
c) 36 x 8 + a = 290
288 + a = 290
a = 290 - 288 = 2
d) (362 - a): 2 = 150
362 -a = 300
a = 362 - 300 = 62
e) 42 : a = 189
42 = 189 x a
a = 42/189 = 14/63 = 2/9
f) (436 - 236) x a = 600
200 x a = 600
a = 3
g) 378 : a = 24
a = 378 : 24 = 378/24 = 189/12 = 63/4
