The perimeter of a rectangle is 32 inches.

The rectangle has a width of 4 inches.
The rectangle has a length of 2.5x inches
Which equation can be used to find the value of x?
A 4+ 2.5x = 32
B. 8 + 5x = 32
C. 4(2.5x) = 32
D. 8(5x)= 32

1 answer

To find the perimeter of a rectangle, you can use the formula:

\[ P = 2 \times (length + width) \]

In this case, the given perimeter \( P \) is 32 inches, the width is 4 inches, and the length is given as \( 2.5x \) inches.

Substituting the values into the perimeter formula, we get:

\[ 32 = 2 \times (2.5x + 4) \]

To simplify this equation, first divide both sides by 2:

\[ 16 = 2.5x + 4 \]

Now, subtract 4 from both sides:

\[ 12 = 2.5x \]

We can re-organize this into a different format to find a suitable option. To do that, we can convert this equation into a comparison of widths and lengths.

The total width in terms of its component form, because there are two widths (4 inches each), is:

\[ 8 \]

And the total length in terms of its component form twice length (2.5x) is:

\[ 5x \]

Putting both sides together gives:

\[ 8 + 5x = 32 \]

Now, looking at the options:

A) \( 4 + 2.5x = 32 \)
B) \( 8 + 5x = 32 \)
C) \( 4(2.5x) = 32 \)
D) \( 8(5x) = 32 \)

The correct option is:

B. \( 8 + 5x = 32 \)