Question 343010
You didn't use any parentheses to differentiate numerators and denominators so this is my guess.
If it's wrong, please repost.
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{{{(a + 4 )/b = (a- 4)/b + (b + 4)/a }}}
Multiply both sides by {{{ab}}}
{{{a(a+4)=a(a-4)+b(b+4)}}}
{{{a^2+4a=a^2-4a+b(b+4)}}}
{{{8a=b(b+4)}}}
{{{highlight(a=(b(b+4))/8)}}}