a)(1*7/8)-x=1/4
x=7/8-1/4
x=(7-2)/8
x=5/8
sau
7/(8-x)=1/4
8-x=28
x=-20
Depinde cum sunt puse parantezele
b)5x=15/16
x=15/16*1/5
x=15/(16*5)
x=15/80
x=3/16
c)(3/4):x=7/8
3/4x=7/8
4x=24/7
x=(24/7)*1/4
x=24/28
x=6/7
sau
3*1/(4:x)=7/8
3/(4:x)=7/8
3x/4=7/8
3x=(7*4)/8
3x=28/8
x=(28/8)*1/3
x=28/24
x=7/6
d)4x/5=2/3
4x=(5*2)/3
4x=10/3
x=(10/3)*1/4
x=10/12
x=5/6
