假设原来的式子是x - y =5.25被减数减少0.5,减数减少0.4即(x-0.5)-(y-0.4)=x - 0.5 - y +0.4 = x -y -0.1那么由于x - y =5.25,所以x -y -0.1 = 5.25-0.1=5.15也就是说现在差是5.15
5.25-(0.5-0.4)=5.15
x-y=z (x-0.5)+(y-0.4)=x-y-0.1=ww+0.1=zz=5.25w=5.25-0.1=5.15
5.15