## anonymous 5 years ago $x ^{-2}-4x ^{-1}=0$ Help me

1. anonymous

This can be rewritten as $1/x^2-1/4x=0$ If you plug this into a TI-89 using the solve function, you get: $x=1/4$ Hope this helps.

2. anonymous

factor the left side into $\frac{1}{x}(\frac{1}{x}-4)=0$and set the factors equal to zero. $\frac{1}{x}=0$ is not true for any real x, so this gives no solutions. $\frac{1}{x}-4=0$ gives $\frac{1}{x}=4$and so, multiplying both sides by x and dividing by 4, $x=\frac{1}{4}$

3. anonymous

got this one :)

4. anonymous

$\frac{1}{x ^{2}}-\frac{4}{x}=10$$Denominator is: x ^{2}$$\frac{1*x}{x ^{2}}-\frac{4*x}{x*x}=10*x^2$get rid with denominator$1-4x=10x ^{2}$$10x ^{2}-4x+1=0$$\frac{-(-4)\pm \sqrt{-4^{2}-(-4\times10\times1)}}{2\times10}$$\frac{4\pm \sqrt{16+40}}{20}$$\frac{4\pm 2\sqrt{14}}{20}$$\frac{2\pm \sqrt{14}}{10}$