Question 427759
perform the indicated operation by using the LCD and simplify the result.
{{{(5x)/(x-7)}}} - {{{(3x)/(7-x)}}}
On the 2nd denominator we can factor out -1, 
{{{(5x)/(x-7)}}} - {{{(3x)/(-1(x-7))}}}
then - 1 changes the sign to
{{{(5x)/(x-7)}}} + {{{(3x)/(x-7)}}}
Now the denominators are the same so we have
{{{(5x + 3x)/(x-7)}}} = {{{(8x)/(x-7)}}}, is the simplified expression