Respuesta :

Answer:

[tex]\dfrac{1}{3}(b-21)[/tex]

Step-by-step explanation:

We need to find an equivalent expression for [tex]\dfrac{1}{3}b-7[/tex]

The denominator of first fraction is 3 and that of other is 1.

[tex]\dfrac{1}{3}b-7\\\\=\dfrac{b-21}{3}[/tex]

or

[tex]=\dfrac{1}{3}(b-21)[/tex]

Hence, the equivalent expression is [tex]\dfrac{1}{3}(b-21)[/tex].

The answer Is 1/3(b-21)