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Francesca wants to glue this 3-inch by 5-inch photo on top of a mat that will increase the length of each side by another x inches. Find an expression representing the area of the mat and use this expression to find the area and cost of the mat for different values of x.

Francesca wants to glue this 3-inch by 5-inch photo on top of a mat that will increase-example-1
User Break
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1 Answer

16 votes
16 votes

The photo along with the mat will be something like this:

So, new side length = 3 + 2x

new height = 5 + 2x

Hence,

Rectangle Area (A) = length * height

Thus,


\begin{gathered} A=(3+2x)(5+2x) \\ A=15+6x+10x+4x^2 \\ A=15+16x+4x^2 \end{gathered}

Francesca wants to glue this 3-inch by 5-inch photo on top of a mat that will increase-example-1
User Ian Renton
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