-2 1x-3 2y z-2 1x 3 4y 1.5z合并同类项
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![-2 1x-3 2y z-2 1x 3 4y 1.5z合并同类项](/uploads/image/f/19946-2-6.jpg?t=-2+1x-3+2y+z-2+1x+3+4y+1.5z%E5%90%88%E5%B9%B6%E5%90%8C%E7%B1%BB%E9%A1%B9)
1)-4x^3-16x^2-26x=-2x(2x^2+8x+13)2)56x^3yz+14x^2y^2z-21xy^2z^2=7xyz(8x^2+2xy-3yz)
=[(X+Z)+(X-Y)]/[X(X-Y)+Z(X-Y)]-[(X+Y)+(X+Z)]/[X(X+Y)+Z(X+Y)]=[(X+Z)+(X-Y)]/[(X+Z)(X-Y)]-[(X+Y)+(X+Z)
x:y=3:2①y:z=5:4②x+y+z=66③,由①得x=32y④,由②得z=45y⑤,把④⑤代入③得32y+y+45y=66,解得y=20,把y=20代入④得x=32×20=30,把y=20代入
本题考查最值不等式:a+b≥2√ab当且仅当a=b时,取等号x√yz+y√zx+z√xy≤x(y+z)/2+y(z+x)/2+z(x+y)/2当且仅当y=z,z=x,x=y,即:x=y=z时,取等号,
(x+y+z)^2=x^2+y^2+z^2+2xy+2yz+2xz>3(xy+yz+zx)所以只要求证x^2+y^2+z^2>xy+yz+zx2(x^2+y^2+z^2)>2(xy+yz+zx)(x^
x²-xy+xz-yz=x(x-y)+z(x-y)=(x+z)(x-y)若仍有疑问,欢迎追问!
=(x+y+z)^2+yz(y+z+x)=(x+y+z)(x+y+z+yz)
解x²-y²-z²+2yz=x²-(y²+z²-2yz)=x²-(y-z)²=(x+y-z)(x-y+z)
如果x/yz^2整体在根号下则lg根号下(x/yz^2)可写成1/2lg(x/yz^2)进一步写成1/2[lgx-lg(yz^2)]最终可以表示为1/2lgx-1/2lgy-lgz运用的公式是lg(x
XYZ-XY-XZ+X-YZ+Y+Z-1XYZ,XY提取公因式XY;XZ,X提取公因式X;YZ,Y提取公因式Y=XY(Z-1)-X(Z-1)-Y(Z-1)+(Z-1)提取公因式(Z-1);=(Z-1)
系数=-8分之1
z²/x²再问:怎么得的再答:原式=x/y²*yz/x²*yz/x=z/xy*yz/x=z²/x²
xyz-yz-zx-xy+x+y+z-1=yz(x-1)-z(x-1)-y(x-1)+x-1=(x-1)(yz-y-z+1)=(x-1)(y-1)(z-1)
图片中的题可以用琴森不等式构造函数f(x)=e^x/(3e^x+1)^0.5可以验证f``(x)>0对所有x成立因此f(x)是下凸函数有f(x)+f(y)+f(z)>=3f(x+y+z/3)令x=ln
16x(125X34+88X125)=2×8×125×(34+88)…………变一变就简便=(8×125)×(2×122)=1000×244=244000
原式=xy(z-1)-x(z-1)-y(z-1)+(z-1)=(z-1)(xy-x-y+1)=(x-1)(y-1)(z-1)其中用到了一个公式:ab+a+b+1=(a+1)(b+1)ab-a-b+1=
答案是:(2*X)/((X-Z)*(X+Z))再问:解题过程给我写下1再答:=(2X+Z-Y)/[(x-y)(x+z)]-(y-z)/[(x-z)(x-y)]=[(2x+z-y)(x-z)-(y-z)
通分原式=[(yz+xz+xy)/xyz]×(xy)/(xy+yz+zx)=xy(yz+xz+xy)/[xyz(xy+yz+zx)]=1/z
◆因为一英寸=2.54厘米,所以换算后的尺寸是:带抽屉的橱柜30.48cmX87.63cmX60.96cm152.4cmX87.63cmX60.96cm1/2是半寸的意思.再问:你好,请问6′6″的桌