Given:
The expression is,
[tex]\frac{4}{a+1}+\frac{5}{a-3}[/tex]
Simpify the expression,
[tex]\begin{gathered} \frac{4}{a+1}+\frac{5}{a-3} \\ \text{Adjust fractions based on least common multiple,} \\ =\frac{4\left(a-3\right)}{\left(a+1\right)\left(a-3\right)}+\frac{5\left(a+1\right)}{\left(a+1\right)\left(a-3\right)} \\ =\frac{4(a-3)+5\mleft(a+1\mright)}{(a+1)(a-3)} \\ =\frac{4a-12+5a+5}{(a+1)(a-3)} \\ =\frac{9a-7}{(a+1)(a-3)} \end{gathered}[/tex]
Answer:
[tex]\begin{gathered} \text{Numerator}=\text{ 9a-7} \\ \text{Denominator}=\text{ (a+1)(a-3)} \end{gathered}[/tex]