1)7,5:3/8= 7 1/2 *8/3= 15/2* 8/3 = 5/1*4/1=20
2)4 2/3 * 0,6=14/3 * 6/10 = 7/1*2/5 = 14/5=2,8
3)20+2,8=22,8
4)2,5:1 3/7 = 5/2 : 10/7 = 5/2*7/10 =1/2*7/2= 7/4 = 1,75
5)1,75+5,25= 7
6)0,5-1/12 = 1/2 -1/12 = 6/12 - 1/12=5/12
7)22,8:1,9=12
8)7:2 1/3 = 7: 7/3 = 7*3/7 = 3
9)2 2/3*0,15 = 8/3 * 15/100 = 2/1*5/25 = 2*1/5= 2/5
10)2/5 : 6/10 = 2/5*10/6 = 1/1*2/3 = 2/3
11)5/12 * 8/10 = 1/3*2/2 = 1/3
12)12:3=4
13)2/3:1/3=2/3*3=2
14)4+2=6
148908+3511=152419 Вот такой ответ.
4х-2х = -7-5
2х = -12
х = -12/2
х = -6
Ответ: -6