solve each system by elimination

Question

15x - y = 3
5x - 10y = 30

im stuck with what to do first

Answer 1

multiply the second line by 3 and ypu have
15x - y = 3
15x - 30y = 90
now subtract and that leaves
29y = -87
y = -3
so, since 15x-(-3) = 3, x=0

Answer 2

I got (6/15 , 3)