Solution:
There are Infinitely many solutions.
Step-by-step explanation:
We have been given the system of equations
![3x+2y=7.......(1)\\\\-9x-6y=-21......(2)](https://img.qammunity.org/2019/formulas/mathematics/college/798k8psju36f3rpz1yjhq9331fh3pkfwrp.png)
In elimination method, we multiply any of the equation by some constant and then add/subtract the equations to eliminate any variable x or y.
Let us multiply equation 1 by 3
![9x+6y=21.......(3)\\\\-9x-6y=-21......(4)](https://img.qammunity.org/2019/formulas/mathematics/college/wt1shcwmm6k9cztgmva4jcettq59suoo30.png)
Add equations 3 and 4, we get
![9x-9x+6y-6y=21-21\\\\0=0](https://img.qammunity.org/2019/formulas/mathematics/college/nusc6igetch359sf6dkemlps3jatc0t2vp.png)
We got 0=0, which is always true.
Hence, there are Infinitely many solutions.
C is the correct option.