2.
1)
9(х-1) = х+15,
9х-9 = х+15,
9х-х = 15+9,
8х = 24,
х = 3,
2)
(11х+14) - (5х-8) = 25,
11х+14-5х+8 = 25,
6х = 25-14-8,
6х = 3,
х = 1/2 (или =0,5),
3)
12- 4(х-3) = 39-9х,
12-4х+12 = 39-9х,
-4х+9х = 39-12-12,
5х = 15,
х = 3,
4)
2(3х+5) - 3(4х-1) = 11,8,
6х+10-12х+3 = 11,8,
-6х = 11,8-10-3,
-6х = -1,2,
х = 0,2 (или = 1/5),
3.
0,3у + 2(0,2у - 0,3) = 0,8- 0,7(у - 2),
0,3у + 0,4у - 0,6 = 0,8 - 0,7у + 1,4,
0,3у + 0,4у + 0,7у = 0,8 + 1,4 + 0,6,
1,4у = 2,8,
у = 2,
0,6 - (1,3х + 1) = 2,8х - 13,52,
0,6 - 1,3х - 1 = 2,8х - 13,52,
-1,3х - 2,8х = -13,52 - 0,6 + 1,
-4,1х = -13,12,
х = 3,2