Answer: The correct option is option third .
Step-by-step explanation:
The given equation are,
![0.8-4x=-0.4y\\6x+0.4y=4.2](https://img.qammunity.org/2019/formulas/mathematics/middle-school/4tllkyyuw9t8zh4t1u1rit55buxypvyrvw.png)
In the second equation the like terms are aligned, therefore, we have to aligened only first equation.
The first equation is,
![0.8-4x=-0.4y](https://img.qammunity.org/2019/formulas/mathematics/middle-school/1wl8zbd0x5aie584ggcdafxb4vnc58ki7x.png)
Subtract 0.8 from both the sides.
![0.8-4x-0.8=-0.4y-0.8](https://img.qammunity.org/2019/formulas/mathematics/middle-school/uj1s70i5b6akdwk5spv5tcdobazgzhtd0b.png)
![-4x=-0.4y-0.8](https://img.qammunity.org/2019/formulas/mathematics/middle-school/nwtlld6glujfkouxqegc1fn8cnxr5xgvjz.png)
Add 0.4y on both the sides.
![-4x+0.4y=-0.4y-0.8+0.4y](https://img.qammunity.org/2019/formulas/mathematics/middle-school/955g2uoxrx32bzw8v97rsxo30gm7w0j23e.png)
![-4x+0.4y=-0.8](https://img.qammunity.org/2019/formulas/mathematics/middle-school/wfl3ly8p3ztli5mjvm9k68ul9ptfmuagqq.png)
So, after aligned the system of equation have two equations.
![-4x+0.4y=-0.8](https://img.qammunity.org/2019/formulas/mathematics/middle-school/wfl3ly8p3ztli5mjvm9k68ul9ptfmuagqq.png)
![6x+0.4y=4.2](https://img.qammunity.org/2019/formulas/mathematics/middle-school/ff1ufxzqehqhed6w5l58kmotl3m4qovxm6.png)
Both equation are show in third option, So third option is correct.