a)4/5*x=8/35 b)1 1/2+x=3/2-7 c)2/3*x+1/4=7/12
x=8/35:4/5 3/2+x=3/2-7 2/3*x=7/12-1/4
x=2/7. 3/2+x=-11/2 2/3*x=1/3
x=-11/2-3/2 x=1/3:2/3
x=-7. x=1/2.
d)1/4+1/3:3x=-5 e)2/3*x:1/5=1 1/3:4
1/3:3x=(-5)-1/4 2/3*x:1/5=1/3
1/3:3x=-21/4 2/3*x=1/3*1/5
3x=1/3:-21/4 2/3*x=1/15
3x=-4/63 x=1/15:2/3
x=-4/63:3 x=1/10.
x=-4/189.
f)(3x/7+1):(-4)=-1/28
(3x/7+1) =-1/28*(-4)
(3x/7+1) =-1/7
3x/7 =-1/7-1
3x/7 =-8/7
Không có kết quả x vì -8 không chia hết cho 3.