The perimeter of the rectangle is 31 inches.

Let x is the width(w) of the rectangle.

The word more than indicates addition operation and its symbol .

The word 3.5 more than its width(w) x indicates the length(l) of the rectangle is .

The perimeter formula for rectangle is .

Substitute the values of in the above formula.

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Apply distributive property: .

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Apply subtraction property of equality: If then .

Subtract 7 from each side.

Apply division property of equality: If then .

Divide each side by 4.

Cancel common terms.

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The width of the rectangle is 6 inches.

The length of the rectangle is inches.

The width of the rectangle is 6 inches and its length is 9.5 inches.