Answer:
x=10, y=5
Step-by-step explanation:
For substitution, you always want to get the variable alone. The second equation (x-2y=0) will be easier to substitute into the first equation.
x-2y=0
x=2y
You can substitute 2y as x on the first equation (x+4y=30).
2y+4y=30
6y=30
y=5
Plug y=5 into any equation.
x+4(5)=30
x+20=30
x=10
