The sides of a rectangle are (4x + 8) cm and (4x + 1) cm. Which expression represents its area?
Note
Area of a rectangle is length × width. Multiply every part: (4x)(4x) = 16x^2, outside and inside terms add to 36x, and 8×1 = 8. So the area is 16x^2 + 36x + 8.