1.(99-5)÷(12+13)=3.76小时兰兰行3.76小时后两人相距99千米设从甲桶里倒出X千克油倒乙桶45-X=1.5(24+X)45-X=36+1.5X2.5X=9X=3.6甲桶里倒出3.6千克油倒乙桶,使甲桶里的油的质量是乙桶里的1.5倍
1、设x小时后相距99km12x+13x+5=99x=3.762、设倒x千克油倒乙桶里45-x=(24+x)×1.5x=3.6