Answer:
Perimeter of the rectangle is 16x+18 units.
Step-by-step explanation:
The area of rectangle is
[tex]7x^2+57x+8[/tex]
First we have to find the factor form of above expression.
Splitting the middle term, we get
[tex]7x^2+56x+x+8[/tex]
[tex]7x(x+8)+1(x+8)[/tex]
[tex](x+8)(7x+1)[/tex]
Area of a rectangle is the product of its dimensions. It means dimensions of the rectangle are (x+8) and (7x+1).
Perimeter of a rectangle is
[tex]Perimeter=2(l+b)[/tex]
[tex]Perimeter=2[(x+8)+(7x+1)][/tex]
[tex]Perimeter=2[8x+9][/tex]
[tex]Perimeter=16x+18[/tex]
Therefore, the perimeter of the rectangle is 16x+18 units.