 So let's try to find the intersection point of the lines with the equation y equals 4x and y plus 2x equals negative 5. So even though this is a geometric question to find the intersection points, because we have the algebraic equations for the two lines, we should try to find this intersection point algebraically by solving the system of equations. Now remember there's two ways of solving systems of equations. We can either use the addition method or we can use the substitution method. In this particular case, we might notice that one equation is already solved for y. And since one equation is already solved for y, we'll use substitution. So we can substitute y equals 4x into our second equation and solve, which gives us our x-coordinate. Now that we know what our x-value is, we'll substitute it into the equation that was already solved for y, and that gives us our y-value, and we'll go ahead and reduce that because the reduction of the fraction isn't too difficult. And so the intersection point occurs when x equals minus 5, 6, y equals negative 10 thirds. So the important thing to remember about working with computers is that computers are stupid. They can't read your mind. They don't understand subtlety, sarcasm, or implication. And so the thing to remember when dealing with computers is it's not what you meant to say, it's what you actually write. So if you write this, the computer doesn't understand it. That's why it says invalid notation. And that's because in this particular case you're supposed to enter your answer as an ordered pair. So we need to separate these values with a comma, and it's still confusing to the computer. And that's because an ordered pair is supposed to be enclosed with parentheses. So we've got to add those parentheses. We'll check one more time. What the computer is hearing is the ordered pair x equals negative 5, 6, y equals negative 10 thirds, which is what we want to say, so we're ready to click on Submit and get full credit for that problem.