(3n/(n-4)-6n/(n^2-8n+16)):(n-6)/(16-n^2)+24n/(n-4)=(3n/(n-4)-6n/(n-4)(n-4))*(4-n)(4+n)/(n-6)+24n/(n-4)=(3n(n-4)-6n)/(n-4)(n-4)*(4-n)(4+n)/(n-6)+24n/(n-4)=(3n²-18n)/(n-4)(n-4)*(4-n)(4+n)/(n-6)+24n/(n-4)=3n(n-6)/(n-4)(n-4)*(4-n)(4+n)/(n-6)+24n/(n-4)=3n(4+n)/(4-n)+24n/(n-4)=3n(4+n)-24n/(4-n)=(12n+3n²-24n)/(4-n)=(3n²-12n)/(4-n)=3n(n-4)/(4-n)=-3n
