Answer:
a = 36
Explanation:
For the system to have no solution, the two lines must have the same slope and different y -intercept, that is, be parallel lines.
The slope of the first line is "-1/2" (negative one half) when we solve for y:
![y = -(1)/(2) x+(11)/(6)](https://img.qammunity.org/2021/formulas/mathematics/college/5zzlccoapc2acfpqj0cntfvoilpmokwppu.png)
so we want the slope of the second line to be the same, and the y-intercept to be different:
![y=-(a)/(72) x+(61)/(36)](https://img.qammunity.org/2021/formulas/mathematics/college/t46xo48utlgaac05dx7s9x0dbk59la5b42.png)
We see that the y-intercepts are different, so all is needed now is to find the appropriate a that gives a slope = -1/2, and that a value is 36.