Height of a painting is twice its width x. You want a 3 inch wide wooden frame for the painting. The area of the frame is 216 square inches. What is the variable expression for the area of the frame alone?

Answer:

Width=X;

Height=2X;

After 3 inch wide

width=(X+3);

Height=2x+3;

Area= (x+3)(2x+3)=2x^+9X+9

so variable expression is

2x^+9X+9=216