Hola, vamos a simplificarlas.
1) [tex]\frac{72}{360} = \frac{36}{180} = \frac{18}{90} = \frac{9}{45} = \frac{1}{5}[/tex]
2) [tex]\frac{42}{105} = \frac{14}{35} = \frac{2}{5}[/tex]
3) [tex]\frac{216}{324} = \frac{108}{162} = \frac{54}{81} = \frac{6}{9} = \frac{2}{3}[/tex]
4) [tex]\frac{180}{2400} = \frac{18}{240} = \frac{3}{40}}[/tex]
Espero haberte podido ayudar
