1.函數(shù)y=（m+2）x+m-1為一次函數(shù),則m+2≠0,m≠-2
y=（m+2）x+m-1為正比例函數(shù),則m-1＝0,m=1
2.（1）函數(shù)圖象與y軸的交點(diǎn)在x軸的下方,則有
當(dāng)x=0時(shí),函數(shù)y=（6+3m）x+（n-4）＜0,n<4,m≠-2.
2）函數(shù)圖象經(jīng)過原點(diǎn),則有當(dāng)x=0時(shí),函數(shù)y=（6+3m）x+（n-4）=0
n=4,m≠-2.