Unit
Linear Equations and Their Graphs
MA, Stanford University
Teaching in the San Francisco Bay Area
Alissa is currently a teacher in the San Francisco Bay Area and Brightstorm users love her clear, concise explanations of tough concepts
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MA, Stanford University
Teaching in the San Francisco Bay Area
Alissa is currently a teacher in the San Francisco Bay Area and Brightstorm users love her clear, concise explanations of tough concepts
Remember that at the y-intercept, the x coordinate is equal to 0, and that at the x-intercept, the y coordinate is equal to 0. To find the y-intercept, set x equal to 0 and solve for y. Likewise, to find the x-intercept, set y equal to 0 and solve for x. Write the results as ordered pairs.
Here I’m given an equation and I’m asked to find the x and y intercepts. Now I could go ahead and graph this guy and look at it from the graph, but it’s helpful to know a shortcut and the shortcut is how to find the x and y intercepts only using Algebra without having to graph it at all.
And here is how I can do it. Remember that in order to find the x intercept, the y value is going to be 0, so I’m going to let y equal to 0. So in my problem up here, I’ll have 2x plus 3 times 0 which is zero, I’m not going to write that. 2x plus 0 equals 12, so my x value is 6. That way I know my x intercept is (6,0). I’m halfway done already.
Now I need to find the y intercept which is a similar process. To find the y intercept, you let x equal 0, so now I’m going to have 2 times 0 which is 0, plus 3y equals 12, so my y value is 4. This is my other intercept (0,4).
These are the problems that the Math isn’t very difficult, but a lot of students get confused like x intercept is that when x is 0? Or is that when y is 0? If you can keep this stuff straight in your head, you’ll find these problems so aren’t bad at all. You can just fly through them.
