1. (4 / x + 2) = ( ? / (x + 2)(x + 1))
2. (4x / x - 1) = ( ? / (x + 1)(x - 1))
Thanks.
If I understand your questions correctly then you have to multiply numerator and denominator so that the value of the quotient doesn't change(?). If so:
to #2:
$\displaystyle \frac{4x}{x-1} = \frac{4x(x+1)}{(x+1)(x-1)} = \frac{4x^2 + 4x}{x^2-1}$
Do #1 in exactly the same way. Post your result, please.