Answer:
[tex]p=6b[/tex]
Step-by-step explanation:
Let
x-----> the length of the rectangle
y----> the width of the rectangle
we know that
The perimeter of rectangle is equal to
[tex]P=2(x+y)[/tex]
[tex]P=p\ cm[/tex]
so
[tex]p=2(x+y)[/tex] -----> equation A
[tex]y=b\ cm[/tex] ----> given problem
[tex]x=2y[/tex] -------> [tex]x=2b\ cm[/tex]
substitute the value of x and the value of y in the equation A
[tex]p=2(2b+b)[/tex]
[tex]p=2(3b)[/tex]
[tex]p=6b[/tex]