a)
9x+28=2755
9x=2755-28
9x=2727
x=2727:9=33
510+14x=762
14x=762-510=252
x=252:14=18
b)
5y-97=943
5y=943+97=1140
y=1140:5=228
410-7y=151
7y=410-151=259
y=259:7=37
c)
3(x+7)=75
x+7=75:3=25
x=25-7=18
14(12-x)=70
12-x=70:14=5
x=12-5=7
d)
(82+y):6=17
82+y=17·6=102
y=102-82=20
(y-33):9=305
y-33=305·9=2745
y=2745+33=2778
e)
111+2x+29=10^3
2x+140=1000
2x=1000-140=860
x=860:2=430
5x+52-31=30^2-19
5x+21=30·30-19
5x=900-19-21
5x=860
x=860:5=172
f)
5(y-2)+3=38
5(y-2)=38-3=35
y-2=35:5=7
y=7+2=9
9+2(14-y)=15
2(14-y)=15-9=6
14-y=6:2=3
y=14-3=11
