((1(целая) 2\5)-1,6): 0,12= 3(целых) 1\2 * (2\3х +4\7) 3\5z+2\3z=3(целых) 4\5

(1 2\5 - 1,6):0,12

1) 1 2\5 - 1,6 = 1 2/5 - 1 6/10 = 1 2/5 - 1 3/5 = - 1/5
2) - 1/5 : 0.12 = - 1/5 : 12/100 = - 1/5 : 3/25 = - 1/5 * 25/3 = - 5/3 = - 1 2/3

3 1\2 * (2\3х +4\7)
1) 3 1\2 * 2\3х = 7/2 * 2/3 x = 7/3x
2) 3 1/2 * 4/7 = 7/2 * 4/7 = 2
7/3x+2=0
7/3x=-2
x=-2 : 7/3 = -2 * 3/7 = - 6/7


3\5z+2\3z=3 4\5
3/5z+2/3z=9/15z+10/15z=19/15z
19/15z=3 4/5 
z=3 4/5 :19/15 (19/5 : 19/15 = 19/5 * 15/19 = 3)
z=3