Пошаговое объяснение:
1)
2(х-6)=3(х+7)
2x - 12 = 3x + 21
3x - 2x = -12 - 21
x = -33
2)
-5(3+2х)=(х-2)9
-15 - 10x = 9x - 18
9x + 10x = 18 - 15
19x = 3
x = 3/19
3)
(4х-3)6=-3(10+6х)
24x - 18 = -30 - 18x
24x + 18x = -30 + 18
42x = -12
x = -12 : 42
x = -2/7
4)
30(8х-10)=6(х-5)
240x - 300 = 6x - 30
240x - 6x = 300 - 30
234x = 270
x = 270 : 234
x = 1 2/13
5)
12(-7-3х)=2(-5х+9)
-84 - 36x = -10x + 18
36x - 10x = -84 - 18
26x = -102
x = -102 : 26
x = -3 12/13
6)
3(5х-15)=(2х+3)4
15x - 45 = 8x + 12
15x - 8x = 12 + 45
7x = 57
x = 57 : 7
x = 8 1/7
7)
(25-15х)2 =-7(5+2х)
50 - 30x = -35 - 14x
30x - 14x = 50 + 35
16x = 85
x = 85 : 16
x = 5 5/16
8)
-5х-12=3(-4+3х)
-5x - 12 = -12 + 9x
9x + 5x = 12 - 12
14x = 0
x = 0
9)
2х=70-5х
2x + 5x = 70
7x = 70
x = 70 : 7
x = 10
10)
-4(-19+23х)=(-21х-2)16
76 - 92x = -336x - 32
336x - 92x = -32 - 76
244x = -108
x = -108 : 244
x = -27/61
Еще 8 мальчиков и 8 девочек . Всего 16 детей .