Answer:
D its
Explanation:
Since x+y = 10-----(1)
And 3x+3y = 30----(2)
We can see from (2) that 3(x+y) =30;
Also same as saying x+y = 30/3 which is equivalent to x+y = 10.
So in this case we have many possible values
x = 0, y = 10 and vice versa
x = 1, y = 9 and vice versa
x = 2, y = 8 and so on
So the question has a lot of solutions