length x+7
width x+3
4x+20
x²+10x+21
x²+21
2x+10
It looks like you provided the expressions for the length and width of a rectangle.
The expression "length x+7" represents the length of the rectangle, which is x+7.
The expression "width x+3" represents the width of the rectangle, which is x+3.
To find the perimeter of the rectangle, you can use the formula P = 2L + 2W, where P represents the perimeter, L represents the length, and W represents the width. Plugging in the given expressions, the perimeter is:
P = 2(x + 7) + 2(x + 3)
= 2x + 14 + 2x + 6
= 4x + 20
So the expression 4x + 20 represents the perimeter of the rectangle.
The expression "x²+10x+21" cannot represent the perimeter since it is a quadratic expression and not a linear expression.
The expression "x²+21" is not related to the rectangle's dimensions or perimeter. It is also a quadratic expression.
The expression "2x+10" does not represent the perimeter but represents another linear expression.