# The perimeter of a rectangular book is 48 inches. How do you express the length of the book as a function of the width?

##### 1 Answer

May 28, 2016

#### Explanation:

Recall that the perimeter of a rectangle is given by,

#color(blue)(|bar(ul(color(white)(a/a)P=2(l+w)color(white)(a/a)|)))# where:

#P=# perimeter

#l=# length

#w=# width

Hence, to create an expression for the length, substitute

#P=2(l+w)#

#48=2(l+w)#

#48/2=l+w#

#l=24-w#

Replacing

#color(green)(|bar(ul(color(white)(a/a)color(black)(f(w)=-w+24)color(white)(a/a)|)))#