x的6次方-x³y的4次方z²-搜答案-大师作文网

设3^x=4^y=6^z=k.x=log3(k)=1/logk(3),y=log4(k)=1/logk(4),z=log6(k)=1/logk(6)1,1/x+1/(2y)=logk(3)+logk(

6x²yz³

3x²y-{xyz-(2xyz-y²z)-4y²z+[3x²-(4xyz-5y²z)]}其中x=-1,y=1/2,z=3=3x²y-xyz+

x^20*y^15*z^5=64=>(x^4*y^3*z^1)^5=64=>s=x^8*y^6*z^2=64^(2/5)=2^(7*2/5)=2^(14/5)

同时取对数令：xlg3=ylg4=zlg6=m则1/x=lg3/m1/y=lg4/m1/z=lg6/m1/z-1/x=(lg6-lg3)/m=lg2/m1/(2y)=(1/2)lg4/m=lg2/m得

-6x^(m+1)·y^m·z²-18x^m·y^(m-1)·z=-6x^m·y^(m-1)·z·(xyz+3)

(x-y)(z+y-x+y+2y)÷4y=(x-y)(z-x+4y)÷4y{(x+y)(x-y)-(x-y)的2次方+2y(x-y)}除以4y=(x-y)(x+y-x+y+2y)÷4y=(x-y)(4

-3x^2y^3z+4x^3y^3z-6x^4yz^2=x^2yz(-3y^2+4xy^2-6x^2z)

设xyz均为正数,且3的x次方=4的y次方=6的z次方,取对数得xlg3=ylg4=zlg6,(1)1/z-1/x=lg6/(ylg4)-lg3/(ylg4)=(lg6-lg3)/(2ylg2)=1/

3^x=4^y=6^zln(3^x)=ln(4^y)=ln(6^z)xln3=yln4=zln6xln3=2yln2=z(ln2+ln3)设xln3=2yln2=z(ln2+ln3)=tln3=t/x

x^20*y^15*z^5=32x^40*y^30*z^10=1024x^8*y^6*z^2=五次根号1024=4

从已知,设3^x=4^y=6^z=10x=log3y=log4z=log6log6>log4>log3=>z>y>x所以6z>4y>3x

3^x=4^y=6^z=t＞0x=log3ty=log4tz=log6t3x=3log3t=log3^(1/3)t4y=4log4t=log4^(1/4)t6z=6log6t=log6^(1/6)t3

设3^x=4^y=6^z=k.(k>1)x=log3(k)y=log4(k)z=log6(k)1/z-1/x=logk(6)-logk(3)=logk(2)1/(2y)=1/2*logk(4)=log

一看就知道X>y>z否则不会出现上述条件如果三X=6Z那么相当于9的z次方=6的Z次方肯定是不对的所以3X6Z所以3X

1.3的x次方=4的y次方=6的z次方xlg3=ylg4=zlg6设：k=xlg3=ylg4=zlg6则：1/x=lg3/k1/y=lg4/k=2lg2/k1/z=lg6/k所以：1/z-1/x=(l

x³-xyz+x²y-x²z=(x³+x²y)-(xyz+x²z)=x²(x+y)-xz(y+x)=x(x+y)(x+z).

3^x=4^y=6^zln(3^x)=ln(4^y)=ln(6^z)xln3=yln4=zln6xln3=2yln2=z(ln2+ln3)设xln3=2yln2=z(ln2+ln3)=tln3=t/x

x^4＋y^4＋z^4－2x^2y^2－2x^2z^2－2y^2z^2＝(x^4＋y^4－2x^2y^2)＋z^4－2x^2z^2－2y^2z^2＝(x^2－y^2)^2－2(x^2－y^2)z^2＋