9x(2016-x)=2016
X là j giúp mình nha
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Thay \(2016=xyz\)vào biểu thức ta được
\(A=\frac{x^2yz}{xy+x^2yz+xyz}+\frac{y}{yz+y+xyz}+\frac{z}{xz+z+1}\)
\(=\frac{x^2yz}{xy\left(1+xz+z\right)}+\frac{y}{y\left(z+1+xz\right)}+\frac{z}{xz+z+1}\)
\(=\frac{xz}{xz+z+1}+\frac{1}{xz+z+1}+\frac{z}{xz+z+1}=\frac{xz+z+1}{xz+z+1}=1\)
Vậy \(A=1\)
Vì \(xyz=2016\)
\(\Rightarrow A=\frac{2016x}{xy+2016x+2016}+\frac{y}{yz+y+2016}+\frac{z}{xz+z+1}\)
\(=\frac{xyz.x}{xy+xyz.x+xyz}+\frac{y}{yz+y+xyz}+\frac{z}{xz+z+1}\)
\(=\frac{x^2yz}{xy+x^2yz+xyz}+\frac{y}{y\left(z+1+xz\right)}+\frac{z}{xz+z+1}\)
\(=\frac{x^2yz}{xy\left(1+xz+z\right)}+\frac{1}{xz+z+1}+\frac{z}{xz+z+1}\)
\(=\frac{xz}{xz+z+1}+\frac{1}{xz+z+1}+\frac{z}{xz+z+1}\)
\(=\frac{xz+1+z}{xz+z+1}=1\)
\(x^4+2016x^2+2017x+2016\)
\(=x^4+2016x^2+2016x+x+2016\)
\(=\left(x^4+x\right)+\left(2016x^2+2016x+2016\right)\)
\(=x\left(x^3+1\right)+2016\left(x^2+x+1\right)\)
\(=x\left(x+1\right)\left(x^2+x+1\right)+2016\left(x^2+x+1\right)\)
\(=\left(x^2+x+1\right)\left(x^2+x+2016\right)\)
9x(2016-x) =2016
2016-x =2016:9
2016-x =224
x =2016-224
x =1792
Vậy x=1792
9 x ( 2016 - x ) = 2016
2016 - x = 2016 : 9
2016 - x = 224
x = 2016 - 224
x = 1792
Vậy x = 1792