 When we solve by substitution, what we want to look for, we want to remember the loneliest variable. Now that's going to be the variable that does not have a number in front of it. It's going to be the easiest variable to solve for. We're very much trained to solve for y, but a lot of time solving for y will leave us with fractions and just gives us something kind of tricky to work with. So if we can make the problem easier for ourselves, we definitely want to do that. So I look at the two equations I can solve for either x or either y, excuse me, and this x right here does not have a number in front of it, so it's lonely. I'm going to go ahead and solve for that x. So if we take this equation, we have x plus 3y equals five, and we want to solve for x, which means this term of 3y, we want to get to the other side. So I'm just going to subtract 3y from both sides. 3y minus 3y cancels, so we have x equals a negative 3y plus five. So pretty easy to solve for a lonely variable. Typically it's just bringing one term to the other side. So now we know that x equals a negative 3y plus five. What we're going to want to do with that is go to the equation we have not used yet. We've been working with the red equation, so I'm going to go to the blue equation. I know that x equals a negative 3y plus five, so we want to substitute this in for the x that we see in the equation. So when I rewrite this, I'm going to say a two, and now when I get to the x, I'm not going to put the x because I know x equals all this down here, a negative 3y plus five, so I'm substituting that in. So two times that negative 3y plus five, and then I keep writing the rest of it. We have our minus 3y equals one, and now we're going to distribute out the two. We have an equation with just y, so we want to go ahead and solve for the y. So we distribute that. We have two times negative 3y, which is a negative 6y. Two times the five is plus ten, minus 3y equals one. We have like terms we can combine, since they're on the same side, we can just combine them as is. Negative y minus 3y is a negative 9y plus ten equals one. Subtract ten from both sides, negative 9y equals a negative nine, and then divide both sides by negative 9, so we have y equal to a one. So y equals one, now we just have to know what x is, so we can plug one into any of the equations really that we've been working with. If we're looking for x, usually there's going to be, since we solved for x, that was a lonely variable at the start, this is going to be the easiest equation to work with, this x equals negative 3y plus five, because all we have to do is plug in for the y right here, a positive one. So we have negative three times one, which is negative three plus five, negative three plus five equals two. So our final answer is an ordered pair, for the x value we got a two, and for the y value we got a one, and that will be our final answer using substitution. To check the answer, we certainly can plug both of those points, the x and y, into both equations. We should get a true statement on both sides, but there's your example for substitution.