Answer:
n=10.
Step-by-step explanation:
[tex]\frac{45}{n^{2}-3n-4 }[/tex] - [tex]\frac{3}{n-4}[/tex] = [tex]\frac{2}{n+1 }[/tex]
[tex]\frac{45}{n^{2}-3n-4 }[/tex] - [tex]\frac{3(n+1)}{(n+1)(n-4)}[/tex] = [tex]\frac{2(n-4)}{(n+1)(n-4) }[/tex]
[tex]\frac{45}{n^{2}-3n-4 }[/tex] - [tex]\frac{3n+3}{n^{2} -3x-4}[/tex] = [tex]\frac{2n-8}{n^{2} -3x-4 }[/tex]
45-3n-3=2n-8
45-3+8=5n
n=50/5=10
