уравнение имеет 3 корня
3х - 6,3 =0 |2x+ 7| =0
3х = 6,3 |2x| = |7|
х = 2,1 |x| =3.5 x м.б. 3,5 и - 3,5
1.5a - a - 3 = a-a + 7.5
0.5a - 3 = 7.5 | +3
0.5 a -3 + 3 = 7.5 + 3
0.5 a = 10.5 | : 0.5
a = 10.5 : 0.5
a = 105 : 5
a = 21
1.8b = 3(b-0.12)
1.8b = 3b - 0.36 | - 1.8b
1.8 b - 1.8b = 3 b - 1.8b - 0.36
0 = 1.2b -0.36 | + 0.36
0+0.36 = 1.2b -0.36 + 0.36
0.36 = 1.2b | : 1.2
0.36 : 1.2 = 1.2 b : 1.2
3.6:12 = b
b = 0.3