解方程{5X+2Y=40,5(1+25%)X+2(1+20%)Y=48.5
问题描述:
解方程{5X+2Y=40,5(1+25%)X+2(1+20%)Y=48.5
答
5X+2Y=40,得:5X=40-2Y,
又因为5(1+25%)X+2(1+20%)Y=48.5
所以1.25(40-2Y)+2.4Y=48.5
0.1Y=1.5
所以y=15
x=2