The perimeter of any shape is the sum of the length of its sides. Since the shape is a rectangle, we know that the sides that are opposite of each other are identical.
If we add all expressions for the side lengths, we get an expression that describes the total perimeter.
(2x-7)+ (2x-7) + (4x+3)+ (4x+3)
Note that whenever we are adding two identical expressions or numbers this can be rewritten using multiplication. Since we have two (2x-7) expressions and two (4x+3) expressions, we can rewrite the expression for perimeter using multiplication by 2.
2 (2x-7)+ 2 (4x+3)
Finally, we know that this expression should equal 112, cm which gives us the last piece of information to write our equation.
2 (2x-7)+ 2 (4x+3)=112
This fits option C. Let's also solve this equation for x.
