1) 5.6 * 3 = 0.4 * (3x + 12)
16.8 = 1.2x + 4.8
1,2x = 16.8 - 4.8
1,2x = 12
x = 12 : 1,2
x = 10
________
2) 8.7 * 2 = 0.5 * (15 + 4x)
17.4 = 7.5 + 2x
2x = 17,4 - 7.5
2x = 9.9
x = 9.9 : 2
x = 4,95
_______
3) 1,2 * (3x + 1,6) = 5 * 2,4
3,6x + 1,92 = 12
3,6x = 12 - 1,92
3,6x = 10,08
x = 10,08 : 3,6
x = 2,8
__________________
4) 5,4 * (4,7x - 4,2) = 3 * 0,9
25,38x - 22,68 = 2,7
25,38x = 2,7 + 22,68
25,38x = 25,38
x = 25,38 : 25,38
x = 1
___________________