解方程组:{2x+5y=15m {5x-3y=-m

问题描述:

解方程组:{2x+5y=15m {5x-3y=-m

2x+5y=15m....(1)
5x-3y=-m....(2)
由(1)+(2)*15得77x-40y=0
x=40t
y=77t
(t为正整数)

2x+5y=15m.(1)
5x-3y=-m.(2)
由(1)*5-(2)*2得31y=77m
所以y=77m/31
再代入(2)式得x=40m/31