Răspuns:
9)
(n x 2+132)-569=143
(nx2+132)=143+569
nx2+132=712
nx2=712-132
nx2=580
n=580:2
n=290
10)
(nx9-84:4):6=16
(nx9-21)=16x6
nx9-21=96
nx9=96+21
nx9=117
n=117:9
n=13
11)
(16x3-300:10)x a-225:15=111
(48-30)x a-15=111
18xa=111+15
18x a=126
a=126:18
a=7
