x-5y=0. (times the top row by 3 and bottom 2x-3y=7. by 5 to get the y values the same)
3x-15y=0
10x-15y=35
as the signs before the y value are the same, subtract the other top values from the bottom. (all excluding the y values).
so: 3-10=-7 and 0-35=-35
-7x=-35
-x=-5
x=5
substitute your x back into any of the two equations, here I'll use 2x-3y=7
2(5)-3y=7
10-3y=7
10-7=3y
3=3y
y=1
hope this helped