mx-y-5=0 ①2x+3my-7=0 ②①×2-②×m得：-2y-3m²y-10+7m=0-y(2+3m²)=7m-10y=(10-7m)/(3m²+1)∴(10-7m)/(3m²+1)＜0m＞10/7①×3m+②得：3m²x-15m+2x-7=0x(3m²+2)=15m+7x=(15m+7)/(3m&...-2y-3m²y-10+7m=0-y(2+3m²)=7m-10-10+7m移項(xiàng)時(shí)為什么不變號(hào)。詳細(xì)點(diǎn)mx-y-5=0①2x+3my-7=0 ②①×2-②×m得：-2y-3m²y-10+7m=0y(2+3m²)=7m-10y=(10-7m)/(3m²+2)∴(10-7m)/(3m²+2)＜0 m＜10/7①×3m+②得：3m²x-15m+2x-7=0x(3m²+2)=15m+7x=(15m+7)/(3m²+2)＞015m+7＞0m＞-7/15∴-7/15＜m＜10/7時(shí)，關(guān)于xy的方程組mx-y-5=0 2x+3my-7=0的解滿(mǎn)足x＞0，y＜0是錯(cuò)了，已經(jīng)改正了。