Explanation
Correct answer: C.
Choice C is correct. It's given that the expression represents the area, in square centimeters, of a rectangular painting, where is the width, in centimeters, of the painting. The area of a rectangle can be calculated by multiplying its length by its width. It follows that the length, in centimeters, of the painting is represented by the expression .
Desmos solution:
Note: The area expression is w(w+29). Since area equals width times length and w is the width, the other factor (w+29) must be the length.
Enter in Desmos:
Reviewed and rewritten by CookSAT
Why the other choices are wrong
Choice A
Choice A is incorrect. This expression represents the width, in centimeters, of the painting, not its length, in centimeters.
Choice B
Choice B is incorrect. This is the difference between the length, in centimeters, and the width, in centimeters, of the painting, not its length, in centimeters.
Choice D
Choice D is incorrect. This expression represents the area, in square centimeters, of the painting, not its length, in centimeters.