a) 2x + 146 ≤ 3 x 126=
2x + 146 ≤ 378=
2x ≤ 378- 146=
2x ≤ 232=
x ≤ 232 : 2=
x ≤ 116
b) 3x + 12 x 18 ≤ 3 x (25 + 16) + 123=
3x + 216 ≤ 3 x 41 + 123=
3x + 216 ≤ 123+123=
3x + 216 ≤ 246=
3x ≤ 246 - 216=
3x ≤ 30=
x≤ 30 : 3=
x≤ 10
c)5x + 10 x 16 ≤ 2 x (16 + 19) + 285=
5x + 160 ≤2 x 35 + 285=
5x +160 ≤70+ 285=
5x +160 ≤ 355=
5x ≤ 355 - 160=
5x ≤ 195=
x ≤ 195 : 5=
x ≤ 39
d) ?