using the substitution method how do I solve this equation?

x+2y=0
y=x-3

x + 2y = 0

y = x-3

Do you have the 'meaning' of y? Yes, you have y = x - 3. So, use that equation in your first equation like this:

x + 2(x-3) = 0

Since y is the same thing as x-3 in the second equation, I can substitute it in the first equation.

Now, expand, simplify and solve for x. When you get the value of x, find the value of y, using the value of x.

I hope it helped! Post your answer! :)