Today’s SAT question of the day is a math question about graphing lines.  Pay attention, because I have seen this type of question too many times to count!

The question asks us for the equation of a line that is parallel to the x-axis and 4 units above the x-axis.  All of the answer choices are x = an integer or y = an integer.

First, let’s figure out if this line is “x = something” or “y = something”.

Two ways to figure this out if you don’t remember the difference between x = lines and y = lines: graph the one you think is right on your calculator, or do some quick sketches. If you think it’s x = 4, try drawing a line that goes through all the points where x = 4.  When y is 0, x is 4.  When y is 1, x is 4.  When y is 2…and so on.

Either way, you’ll see pretty quickly that you need a y = line in order for the line to be parallel to the x-axis.

“4 units above the x-axis” is going to be found where y = 4.  It’s not -4 because that would be below the x-axis. E is the right choice today, but it’s more important to remember how to solve this question because it’s highly likely that this concept will be on your test.