Given:
![\begin{gathered} f(x)=2x+1 \\ x=3 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/b8m1aitduxsbd1hgwn513mo0x30k3digm9.png)
Parallel line slope are also same then parallel line equation is:
![f(x)=2x+k](https://img.qammunity.org/2023/formulas/mathematics/college/siuvf0gmdfsgm2p1jnk9zyrvpcs08pm7ph.png)
The line pass (2,7) then:
![\begin{gathered} f(x)=2x+k \\ 7=2(2)+k \\ 7=4+k \\ k=7-4 \\ k=3 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/ylf0ty3txtxqodh3a4catal4fq25wd26sk.png)
So two parallel line equation is :
![\begin{gathered} f(x)=2x+1 \\ f(x)=2x+3 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/wewyz0ejhih0oep492t0p5r485n522p00p.png)
As the difference in y intrcepts is 2.
The side of parallelogram along y- axis is 2.
Two other parallel line are x=0 and x=3
so vertical distance between them is 3
so area is:
![\begin{gathered} \text{Area}=2*3 \\ =6 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/o359n76sa7c2osbyk9rndqmqmkfwgtz8a5.png)