74k+xy2

许才绿4905先化简,在计算2(x2y+xy2) - 3(yx2 - xy2)? -
昌壮甘18498458601 ______ 此题只能化简.2(x²y+xy²)-3(yx²-xy²)=2xy(x+y)-3xy(x-y)=xy(2x+2y-3x+3y)=xy(5y-x)

许才绿4905分解因式:x3 - 2x2y+xy2 -
昌壮甘18498458601 ______ x3-2x2y+xy2,=x(x2-2xy+y2),=x(x-y)2.

许才绿4905分解因式:x3+xy2 - 2x2y -
昌壮甘18498458601 ______ x³+xy²-2x²y=x(x²+y²-2xy)=x(x-y)²

许才绿4905先化简,再求值:(1)2(x2y+xy2) - 2(x2y - 1) - 3xy2 - 2,其中x= - 2,y=12(2) - 2(mn - 3m2) - (mn+6m2)+2 -
昌壮甘18498458601 ______ (1)原式=2x2y+2xy2-2x2y+2-3xy2-2=-xy2,当x=-2,y=1 2 时,原式=-(-2)*(1 2 )2=-1 2 ;(2)原式=-2mn+6m2-mn-6m2+2mn=-mn,当m=1,n=-2时,原式=-1*(-2)=2.

许才绿4905已知x+y=8,xy=12,求x方y+xy2次方的值 -
昌壮甘18498458601 ______ x方y+xy2次方=xy(x+y)=12*8=96

许才绿4905一定量的液态化合物XY2,在一定量的O2中恰好完全燃烧,反应方程式为:XY2+3O2=XO2+2YO2成物的体积是672ml冷却后,在标准状况下测得生成物的... -
昌壮甘18498458601 ______[答案] 因为消耗3个O2 得到3个生成物分子 则消耗的O2分子数和生成物的分子数相等, 分子数相等,则标况体积相等

许才绿4905整式加减练习题(人教版六年级下册)谢了 -
昌壮甘18498458601 ______ 1.3ab-4ab+8ab-7ab+ab=2.7x-(5x-5y)-y=3.23a3bc2-15ab2c+8abc-24a3bc2-8abc=4.-7x2+6x+13x2-4x-5x2=5.2y+(-2y+5)-(3y+2)6...

许才绿4905化简:(1)12a - 3(4a+5b)+2(3a - 4b);(2)3x2y - [2xy2 - 3(xy - 32x2y)+xy]+3xy2 -
昌壮甘18498458601 ______ (1)原式=12a-12a-15b+6a-8b=6a-23b;(2)原式=3x2y-2xy2+3xy-9 2 x2y-xy+3xy2=-3 2 x2y+2xy+xy2.

许才绿4905分解因式:x - 2xy+xy2=______. -
昌壮甘18498458601 ______[答案] x-2xy+xy2, =x(1-2y+y2), =x(y-1)2. 故答案为:x(y-1)2.

许才绿4905已知X+Y=6,xy=4,则求X²Y+XY²的值 -
昌壮甘18498458601 ______ 已知X+Y=6,xy=4,则求X2Y+XY2的值X2Y+XY2=XY(X+Y)=6*4=24