Often it’s the easy things we tend to “mess up” and from my experience when students graph one variable lines they make mistakes not because it’s hard rather they just never remember if y = a number or x = a number is a vertical line or horizontal line. Let’s do a quick review of graphing one variable lines. If you are asked to graph a line that has the equation x=5 this would be a vertical line that goes through 5 on the x-axis. Hence x= a number lines are vertical lines that goes through the respective number in the equation on the x-axis. Now lets take a look at a like that is y = a number for example y = -2. One variable linear equations where y= a number are horizontal lines going through the number. So in this example y= -2 would be a horizontal line passing through -2 on the y-axis. As I said from the start this stuff is easy but it’s also easy to confuse- take a look at the lesson below it should really help you memorize this once and for all!
concepts to remember about graphing one variable linear equations:
1. x= a number are vertical lines
2. y = a number are horizontial lines
3. vertical lines have no slope it’s what we call undefined
4. horizontial lines have a slope = 0
5. line equations are call “linear equations”