Respuesta :

If

[tex]\frac{3}{4}+\frac{1}{5}=\frac{4}{9}[/tex]

That would imply that 9 is a common multiple of 4 and 5, which is false since 9=3^2.

Additionally, 3/4 is greater than 4/9; so 3/4+1/5 has to be greater than 4/9.