Respuesta:
[tex]\frac{7}{8}- \frac{2}{9} =\\\\\frac{63}{72}-\frac{16}{72}\\\\\mathrm{Aplicar\:las\:propiedades\:de\:las\:fracciones}:\quad \frac{a}{c}-\frac{b}{c}=\frac{a-b}{c}\\\\\frac{63}{72}-\frac{16}{72}=\frac{63-16}{72}\\\\=\frac{63-16}{72}\\\\=\frac{47}{72}[/tex]
