You can put this solution on YOUR website! The first thing that needs to be done is to put both fractional expressions over a common denominator:
{1/(5-x)}-{ 4/(5+x)} = (5+x)/{(5-x)*(5+x)}-4*(5-x)/{(5-x)*(5+x)}
Then subtract the two fractional expressions
Finally, simplify both the numerator and the denominator
= {(5+x)-4*(5-x)}/{(5-x)*(5+x)}= (5+x-20+4x)/(25-x^2)=(5x-15)/(25-x^2)
=5*(x-3)/(25-x^2)