For 2x-5y=16, 6x-15y=30 I think there are zero number of solutions.

2 answers

I used the elimination method and got 0=0. Does that mean zero number of solutions?
Actually you made an error:
2x-5y=16, 6x-15y=30
multiply the first by 3 ---->
6x - 15y = 48
subtract the second
0 = 18

If your variable drops out and you end up with a true statement, such as your 8=8, then you have an infinite number of solutions. You are trying to intersect the line with itself.

If your variable drops out and you end up with a false statement, such as 0=5, then there is no solution , you would have two parallel lines