Answer:
There are infinitely many solutions.
Explanation:
3x + 2y = 7
-9x - 6y = -21
Now multiply the first equation by 3
3 × 3x + 2y = 7 ➡ 9x + 6y = 21 Now subtract second equation from first equation
9x + 6y - 9x - 6y = 21 - 21
0 = 0
The equation has infinitely many solutions meaning whatever value you write instead of x and y there will be solution.