Tìm x, biết

Tìm x biết 
a, 4/7×x+2/5=-1/5
b, 2/9-7/8×x=1
c, 4/5+7/6:x=1/6
d, 5/7÷x-1=2/3
e, 1/5 +5/3÷x=1/2