Math Help - need urgent help

1. need urgent help

I need help with these, step by step solution PLEASE HELP

3-2/y
1/y+4

2x- x 2 - x
2-x

x-1 - x+1
x+1 x-1
x-1
+ x+1
x+1 x-1

2. Re: need urgent help

Originally Posted by flor
I need help with these, step by step solution PLEASE HELP

3-2/y
1/y+4

2x- x 2 - x
2-x

x-1 - x+1
x+1 x-1
x-1
+ x+1
x+1 x-1
None of these make any sense. Please rewrite it using parenthesis.

-Dan

3. Re: need urgent help

Hello, flor!

I can guess what the last one says.
The others need parentheses and careful typing.

$\displaystyle \frac{\;\dfrac{x-1}{x+1} - \dfrac{x+1}{x-1}\;}{\dfrac{x-1}{x+1} + \dfrac{x+1}{x-1}}$

Multiply top and bottom by $(x-1)(x+1)$

. . $\dfrac{(x-1)(x+1)\left(\dfrac{x-1}{x+1} - \dfrac{x+1}{x-1}\right)}{(x-1)(x+1)\left(\dfrac{x-1}{x+1} + \dfrac{x+1}{x-1}\right)} \;=\;\dfrac{(x-1)^2 - (x+1)^2}{(x-1)^2 + (x+1)^2}$

. . $=\;\frac{(x^2-2x+1) - (x^2 + 2x + 1)}{(x^2-2x+1) + (x^2 + 2x + 1)} \;=\;\frac{\text{-}4x}{2x^2+2} \;=\;\frac{\text{-}2x}{x^2+1}$