1)х-3/4=6*(3/8-1/6)

х-3/4=18/8-6/6

х-3/4=9/4-1

х=9/4+3/4-1

х=(9+3)/4 - 1

х=(12/4)-1

х=3-1=2

2)х-7/15=-4*(3/4-1/2)

х-7/15=-4(3/4-2/4)

х-7/15=-4*1/4

х-7/15=-1

х=-1+7/15

х=-15/15+7/15

х=-8/15

3)2/5+х=-2(2/3-1/6)

2/5+х=-4/3+2/6=-4/3+1/3=-3/3=-1

х=-1-(2/5)=-1-0,4=-1,4