A square can be changed into a rectangle by increasing the width by 3 units. Which expression represents the area of the rectangle in square units? (A) x^2+8x+15 (B) x2+15 (C) 2x +8 (D) 2x+15
Letting x be the side-length of the square, the new rectangle has length x and width x+3. Thus, the area is (x)(x+3)=x^2+3x. This is not an answer choice.
