15除x=5/6 5x=15*6x=3*6x=18
15÷x=6/5 两侧同乘以5x得:15÷x × 5x=6/5 ×5x75=6xx=75/6x=25/2x=12.5
15÷x=5/65x=15*6x=90÷5x=18
5X=6×155X=90X=18
X=16