## Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)

$$9x^2+24x+16$$
To find the total area of all of the shaded rectangles, we multiply the length of the overall rectangle by the width of the overall rectangle. Doing this, we find: $$\left(3x+4\right)^2 \\ \left(3x\right)^2+2\cdot \:3x\cdot \:4+4^2 \\ 9x^2+24x+16$$