Respuesta :

Answer:

Step-by-step explanation:

[tex]\frac{a}{4}=\frac{b}{7}\\a=\frac{4b}{7} \\\frac{a-b}{b} =\frac{\frac{4b}{7}-b }{b} \\=\frac{4b-7b}{7b}\\ =\frac{-3b}{7b}\\ =\frac{-3}{7}[/tex]