SOS.4道簡(jiǎn)單數(shù)學(xué)題.
1 若4x^3m-1與-3x^5 y^2n+1是同類項(xiàng),求m+n
2 多項(xiàng)式-x^m+(n-)x+1為關(guān)于x的二次二項(xiàng)式,則m=_____ n=_____
3 已知m、n為正整數(shù),單項(xiàng)式（n-2m）x^n+1y^m+1為5次單項(xiàng)式,1 求m n的值 2 當(dāng)x=-1 y=1時(shí),求次單項(xiàng)式的值
4 已知m x y滿足條件：① 1/2（x+2）^2+2/m-2/=0 ② -3^3b^y-1與 5/2b^2a^3是同類項(xiàng),求代數(shù)式 (2x^2-3xy+6y^2)-m(3x^2-xy+9y^2）的值
O(∩_∩)O謝謝 今晚急求