Question

解方程组：x+y=42 ,与(1+0.8%)x+(1+1.1%)y=42乘以(1+1%),xy的解

Answer 1

由x+y=42 得x=42-y,代入(1+0.8%)x+(1+1.1%)y=42x(1+1%),得

(1+0.8%)（42-y）+(1+1.1%)y=42x(1+1%）,

解得,y=28 ,

则x=14