Respuesta :

First we will find out the values of a
a/4=b/7
a=4b/7

Now
(a-b)/b
{4b/7-b}/b
(4b-7b)/7b
-3b/7b
-3/7

The value is [tex]\dfrac{-3}{7}[/tex].

Rational number

It is in the form of numerator and denominator.

Given

[tex]\dfrac{a}{4} =\dfrac{b}{7}\\\\{a} =\dfrac{4b}{7}[/tex]

How to calculate?

[tex]\dfrac{(a-b)}{b} \\\\\dfrac{(\dfrac{4b}{7} -b)}{b}\\\\\dfrac{(\dfrac{4-7}{7} )b}{b} \\\\\dfrac{-3}{7}[/tex]

Thus, the value is [tex]\dfrac{-3}{7}[/tex].

More about rational number link is given below.

https://brainly.com/question/9466779