Express the formula [tex]P = 2l + 2w[/tex] in terms of the width, [tex]w[/tex]. Use the formula to find the width when the perimeter is 70 and the length is 22.

A. [tex]w = \frac{P}{2} - 1[/tex]; [tex]w = 13[/tex]

B. [tex]w = \frac{P - l}{2}[/tex]; [tex]w = 24[/tex]

C. [tex]w = P - 21[/tex]; [tex]w = 26[/tex]

D. [tex]w = \frac{P - 2l}{2}[/tex]; [tex]w = 9[/tex]



Answer :

Certainly! Let's start by expressing the given formula [tex]\( P = 2l + 2w \)[/tex] in terms of the width [tex]\( w \)[/tex].

First, we isolate [tex]\( w \)[/tex] in the equation:

1. The given formula is:
[tex]\[ P = 2l + 2w \][/tex]

2. Subtract [tex]\( 2l \)[/tex] from both sides to isolate the terms involving [tex]\( w \)[/tex]:
[tex]\[ P - 2l = 2w \][/tex]

3. Divide both sides of the equation by 2 to solve for [tex]\( w \)[/tex]:
[tex]\[ w = \frac{P - 2l}{2} \][/tex]

Now, we use this formula to find the width [tex]\( w \)[/tex] when the perimeter [tex]\( P \)[/tex] is 70 and the length [tex]\( l \)[/tex] is 22:

1. Substitute [tex]\( P = 70 \)[/tex] and [tex]\( l = 22 \)[/tex] into the formula:
[tex]\[ w = \frac{70 - 2 \cdot 22}{2} \][/tex]

2. Calculate the expression inside the parentheses first:
[tex]\[ 70 - 2 \cdot 22 = 70 - 44 = 26 \][/tex]

3. Now divide 26 by 2:
[tex]\[ w = \frac{26}{2} = 13 \][/tex]

Therefore, the width [tex]\( w \)[/tex] is [tex]\( 13 \)[/tex].

This matches the fourth option given in the problem:

[tex]\[ w = \frac{P - 2l}{2} ; w = 13 \][/tex]