Since the denominators of the two fractions are different, we need to make them same and then add the two fractions
[tex] \frac{5}{ m^{2} n^{2} } + \frac{m}{n} \\ \\
[/tex]
LCM is m²n² . So we can write:
[tex] \frac{5}{ m^{2} n^{2} } + \frac{m}{n} \\ \\
= \frac{5}{ m^{2} n^{2} }+ \frac{m(m^{2}n) }{ n(m^{2} n) } \\ \\
= \frac{5}{ m^{2} n^{2} }+\frac{m^{3}n }{ m^{2} n^{2} } \\ \\
= \frac{5+m^{3}n}{m^{2} n^{2} } [/tex]