Answer:
a.
![y=2x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/qeikkehr3tck2vx09s7uvb1jwawqh078s6.png)
b.
![y=2x+3](https://img.qammunity.org/2020/formulas/mathematics/high-school/wjby76npdso1i2mnj7d81awhyagwleoivg.png)
Explanation:
We are given that a line
![y=x](https://img.qammunity.org/2020/formulas/mathematics/high-school/ej2majjqavb3ekl29vf4wt62evok5ita1h.png)
a. We have to find the equation of resulting line when the given line is dilated by a factor of 2.
We know that when a line is dilated by a then equation of line is given by
![y=ax](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ur7zq4vkqyh68pigtb1d6glgxwgj60hva4.png)
We have a=2
Then, equation of line after dilation
![y=2x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/qeikkehr3tck2vx09s7uvb1jwawqh078s6.png)
b.We have to find the equation of line when resulting line is translated 3 units up
Transformation rule when the y shift 3 units upward is given by
![(x,y)\righarrow (x,y+3)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/kahqdkfdyrxnvmv0u4rbi6xpx2mog2kcej.png)
When the line
is translated 3 units up then the equation of line is given by
![y=2x+3](https://img.qammunity.org/2020/formulas/mathematics/high-school/wjby76npdso1i2mnj7d81awhyagwleoivg.png)