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

$$78t^2+40t$$
We know the following equation for the area of the shaded region: $$A_{shaded}=\text{Overall Area} - \text{ Area Not Shaded}$$ Using this, we find: $$A=(21t+8)(4t)-(2t(3t-4)) \\ 84t^2+32t-6t^2+8t\\ 78t^2+40t$$