Question

已知方程组x＋2y＝3m x-y＝9m,得解满足5x＋8y＝38,求m的值

Answer 1

根据x-y=9m,得x=9m+y,带入x+2y=3m,得9m+y+2y=3m,得出y=-2m

将y=-2m带入x=9m+y,得到x=7m,

将x=7m,y=-2m带入5x+8y=38,

得35m-16m=38,

19m=38,得出m=2