Question

Margot is sewing a ribbon on a seam along the perimeter of a square pillow. The side length of the pillow is 2x2+1 inches. She plans to make a similar pillow, including the ribbon, whose side length is 4x−7 inches. What expression can be used for the length of ribbon that she needs for both pillows, and what is the length if x = 3.5?

A. 2x2+4x−6; 22.0 inches
B. 2x2+4x−6; 32.5 inches
C. 4(2x2+4x−6;) 88.0 inches
D. 4(2x2+4x−6;) 130.0 inches

Answer 1

Each pillow needs ribbon equal to its perimeter = 4 × side. For both pillows total ribbon = 4[(2x^2+1) + (4x−7)] = 4(2x^2+4x−6).

If x = 3.5: 2(3.5)^2+4(3.5)−6 = 24.5+14−6 = 32.5, and 4·32.5 = 130 inches.

Answer: D.