1) 2,16а - 0,7а + 1,04а =11,77
(2.16-0.7+1.04)а=11.77
2.5а=11.77
а=11.77:2.5
а=4.708
2) 15,05b + 3,2b - b =34,5
(15.05+3.2)b-b=34.5
18.25b-b=34.5
17.25b=34.5
b=34.5:17.25
b=2
3) 4,8d + 5,91 + 13,2d =150
(4.8+13.2)d=150-5.91
18d=144,09
d=144.09:18
d=8.005
4) 0,2с + 1,6с + 1,1 =52,5 + 3,5
(0.2+1.6)с+1.1=52,5 + 3,5
1.8с+1.1=56
1.8с=56-1.1
1.8с=54.9
с=54.9:1.8
с=30.5
5) (2,3х +0,9) : 0,04 - 19,176 =9,074
2,3х +0,9 : 0,04 - 19,176 =9,074
2.3x+22.5-19.176=9.074
2.3x+3.324=9.074
2.3x=9.074-3.324
2.3x=5.75
x=5.75:2.3
x=2.5