求函数,y等于x加x分之四的值域.-搜答案-搜搜做题作业网

令a=x/2=y/3=-z/5x=2a,y=3a,z=-5a则原式=(4a+3a-15a)/(2a)=-8a/2a=-4

x^2-2x+y^2+6y+10=0x^2-2x+1+y^2+6y+9=0(x-1)^2+(y+3)^2=0x-1=0,y+3=0x=1,y=-3(x-y)/(x+y)=4/(-2)=-2

y=2分之x的平方减7x加3

y=x-7分之1+√(x+7)x+7≥0x≥-7但x-7≠0,即x≠7所以定义域为{x|x≥-7但x≠7}再问：谢了

稍等再问：在再答：正在做再答：不好意思再问：哦再答：x-4yx=-4yx-4xy+4y=0(x-2y)=0∴x-2y=0∴x=2y∴原式=(2y+4y)/(2y+y)=6/3=2再答：懂了吗再问：ok

题有错吧,没负号吧

通分原式=[(√x)²+(√y)²]/(√x*√y)=(x+y)/√(xy)=5/√4=5/2

你现在高一么?如果是,那就应该是印刷问题应该是4的y次方吧x=lg36/lg3,y=lg36/lg42/x+1/y=(2lg3+lg4)/lg36=1

y=x^2-4x+5

X=六分之一Y=四分之一Z=三分之一

此题简单做法你直接可以设X=1,Y=0.5,使其满足前面的条件即可,带入后面分式,后面的式子中文表述不清,

3∵x/y=1/2∴y=2x故（x^2+2xy+y^2)/(x^2-xy+y^2)=(x+y)^2/(x^2-xy+y^2)=(x+2x)^2/(x^2-x·2x+4x^2)=9x^2/(3x^2)=

x/3=y/4=z/5x=3/4y,z=5/4y(x+y-z)/(x-y+z)=(3/4y+y-5/4y)/(3/4y-y+5/4y)=1/2y/y=1/2

x/2=y/3=z/4=tx=2ty=3tz=4t(x+y-2z)/(2x-y)=(2t+3t-8t)/(4t-3t)=-2

首先分母有理化,上下同乘以根号x加根号y,然后变成了（x+2乘以根号下xy+y）/(x-y)对xy=4开平方,得到根号下xy=2,（x-y）^2=(x+y)^2-4xy=9,你再开一下方就可以了得到（

x^2+y^2-10x-12y+61=(x-5)^2+(y-6)^2=0,——》x=5,y=6,——》x/y-y/x=5/6-6/5=-11/30.

x/y+y/x=(x²+y²)/xyx²+y²=(x+y)²-2xy=36-16=20原式=20/8=2.5

(x＋y)/(x)=31＋(y/x)=3得：y/x=2则：(x²＋y²)/(x²－xy＋y²)【分子分母同除以x²】=[1＋(y/x)²]/