已知8的x分之1次方=10

4^x≤(1/4)^(x-2)≤4^(x+10)=>4^x≤4^(2-x)≤4^(x+10);4^t是增函数=>x≤2-x≤x+10=>2x≤2&-8≤2x=>-4≤x≤1y=(1/2)^x=2^(-

左边＝(9^x*10^y*16^z)/(8^x*9^y*15^z)=3^(2x-2y-z)*(2^y+4z-3x)*5^(y-z)=2^1所以2x-2y-z=0y-4z-3x=1y-z=0x=-1/5

因为x²-3x+1=0两边同除以x得：x-3+1/x=0,即x+1/x=3两边平方得：：x²+2*x*1/x+1/x²=9即x²+1/x²=7再两边平

x^2+1=3x两边平方x^4+2x^2+1=9x^2x^4+1=7x^2两边除以x^2x^2+1/x^2=7

x10+x6+x4+1分之x10+x8+x2+1=x20+1分之x20+1=1太简单了吧…………

10的x次方=2,10的y次方=9.100的2x-2分之1y次方=10^(4x-y)=(10^x)^4/10^y=2^4/9=16/9

∵374的x次方=1000,0.374的y次方=1000∴374^xy==1000^y,0.374^xy=1000^x两式相除得1000^xy=1000^(y-x)∴xy=y-x∴x分之1-y分之1=

易知,函数f(x)=[10^x-10^(-x)]/[10^x+10^(-x)].的定义域为R.换元.可设t=10^x.x∈R,∴t＞0.故问题可化为求函数g(t)=[t-(1/t)]/[t+(1/t)

x+1/x=2(x+1/x)^2=4x^2+2+1/x^2=4x^2+1/x^2=2

4.17^x=1000,4.17=1000^(1/x)417^y=1000,417=1000^(1/y)4.17/417=1000^(1/x)/1000^(1/y)0.01=1000^(1/x-1/y

x+1/x=10x^2/(x^4+x^2+1)=1/(x^2+1+1/x^2)=1/[(x+1/x)^2-1]=1/(10^2-1)=1/99

x^(1/2)+x^(-1/2)=3求x^2+x^(-2)-(x^(3/2)+x^(-3/2))/2-3解:x^(1/2)+x^(-1/2)=3两边平方,得x+x^(-1)+2=9即x+x^(-1)=

f(x)上下乘10^xf(x)=(10^2x-1)/(10^2x+1)=(10^2x+1-2)/(10^2x+1)=(10^2x+1)/(10^2x+1)-2/(10^2x+1)=1-2/(10^2x

f(x)=a^x+(x-2)/(x+1)在（-1,正无穷）上取点(x1,0)(x2,0),且x1>x2则f(x1)-f(x2)=a^x1-a^x2+(x1-x2)/[(x1+1)(x2+1)]因为x1

平方就行了.x的平方+x平方分之1=11x的4次方+x的4次方分之1=123再问：详细点......谢谢再答：弄错了

∵x^(1/2)+x^(-1/2)=8∴(x²+1)/x=x+1/x=x+x^(-1)=[x^(1/2)]²+[x^(-1/2)]²+2-2=[x^(1/2)+x^(-1

7分之1xy的2次方乘14(xy)的2次方乘4分之1x的5次方=1/7xy²*14(xy)^2*1/4x^5=2x^8*y^4=2*(4)^8*(-1/8)^4=2*2^16*2^(-12)

2x-2/x=32x^2-3x-2=0x1=-1/2x2=2x^4+1/x^4=1/16+16=157/16x^4+1/x^4=16+1/16=157/16

x的2次方+y的2次方-8x-10y+41=0x²-8x+16+y²-10y+25=0(x-4)²+(y-5)²=0由非负性x-4=0y-5=0解得x=4y=5

①∵x²+3x-1=0∴x+3-1/x=0∴x-1/x=-3②(1+1/x)²=(1-1/x)²+4=(-3)²+4=13