Answer:
[tex]4x^2+28x+49[/tex]
Step-by-step explanation:
To find the polynomial, we must first find the side lengthts of the square.
The side length in your image is x 7 x, which equates to 2x+7. This is because we combine the 2 x's, and then add the 7. The area of a square is: [tex]l^2[/tex]
Since our l = 2x+7, the total area would be [tex](2x+7)^2[/tex] or:
[tex](2x+7)(2x+7)=a[/tex]
Now to find the answer, we can use foil.
The formula for foil is:
[tex](a+b)*(c+d) = ac+ad+bc+bd[/tex]
So using the formula, we can plug in our values to get:
[tex](2x+7)(2x+7) = (2x*2x)+(2x*7)+(2x*7)+(7*7)[/tex]
This equates to:
[tex](4x^2)+(14x)+(14x)+(49)[/tex]
Which can then be simplfied into:
[tex]4x^2+28x+49[/tex]
This is our answer!
Hope it helps :3