(1)
2x+1/6x=39/4
13/6x=39/4
x=9/2
(2)7/8x-2/7=3/4
7/8x=3/4+2/7=21/28+8/28=29/28
x=58/49
(3)3/4y-3/5y=3/10
15/20y-12/20y=3/10
3/20y=3/10
y=2