Question 328430
Subtract and simplify if possible
{{{d/(s+d) - d/(s-d)}}}
:
The common denominator; (s+d)(s-d), therefore we have
{{{(d(s-d) - d(s+d))/((s+d)(s-d))}}}
:
Multiply what's inside the brackets
{{{(ds - d^2 - ds - d^2)/((s+d)(s-d))}}}
:
Combining like terms we have
{{{(-2d^2)/((s+d)(s-d))}}}
:
FOIL the denominator (the difference of squares)
{{{(-2d^2)/(s^2 - d^2)}}}  
Or
{{{-(2d^2)/(s^2 - d^2)}}}