The sides of a rectangle are (8x + 1) cm and (2x + 4) cm. Which expression represents its area?
Note
Area of a rectangle is length × width. Multiply every part: (8x)(2x) = 16x^2, outside and inside terms add to 34x, and 1×4 = 4. So the area is 16x^2 + 34x + 4.