设乙数为X,那么甲数为(X-10)
3/4(X-10)=5/6×-10
3/4X-30/4=5/6X-10
5/6X-10-3/4X+30/4=0
1/12X-10/4=0
1/12X=10/4
X=30
甲数=(X-10)=30-10=20