1)
a) 5/8-7/12=15-14/24=1/24
b)18*3 4/9 = 18 * 31/9 = 62
c) (2/5+16/5):4/9=18/5:4/9=18/5*9/4=81/10=8.1
2) 3-2(5-6x)=14x-18
3-10+12x-14x+18
-2x+11=0
2x-11=0
2x=11
x=5.5
3) -3.6 / -3.6+2.4 * 2.4 = -3.6 / -1.2 * 2.4 = 3 * 2.4 = 7.2
Все, на четверку хватит!!!