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