Hello
The formula of the total surface area of this figure is
![\begin{gathered} 2lw+2lh+2hw \\ 2(5* x)+2(3*5)+2(x*5) \\ 10x+30+10x=20x+30 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/ahkjztl99t29y9hpa0u4y7d61xyqfyh989.png)
The total surface area of this figure is 20x + 30
The polynomial that represents the total surface area of the figure is
20x + 30.
Now we have to find the surface area of figure a
3 by 5 by 3
The surface area for figure a is
![2(3*5)+2(5*3)+2(3*3)=78units^2](https://img.qammunity.org/2023/formulas/mathematics/college/1da2r45vgkg1jwh888nd0oyt2sy1fo6qf1.png)
The surface area for figure b is
3 by 5 by 5
![2(3*5)+2(5*5)+2(5*3)=110units^2_{}](https://img.qammunity.org/2023/formulas/mathematics/college/wogq9czq94o86fj0s3a3blgql6idwy502g.png)
The surface area of figure c is
3 by 5 by 12
![2(3*5)+2(3*12)+2(5*12)=222units^2](https://img.qammunity.org/2023/formulas/mathematics/college/p4rdasqzo3rfjv4usjrhz07ght0dr6fcj8.png)
The surface area for figure d is
3 by 5 by 14
![2(3*5)+2(5*14)+2(3*14)=254units_{}](https://img.qammunity.org/2023/formulas/mathematics/college/evqkosphq5a3yh1hcr7vpoj2qw96kf195v.png)
From the calculations above, the surface area of figure a, b, c and d are 78 units, 110 units, 222 units and 254 units respectively