Algebra I Drill 3 Problem 3. What is the x-intercept of the equation?
|Algebra||Coordinates and Graphs|
|Algebra I||x- and y-intercepts|
|CAHSEE Math||Algebra I|
|Systems of Equations||Graphing|
That is, the x intercept is where the line crosses the x axis like… here… and the
y axis is where it crosses… yes, shocker… the Y axis… here.
So to solve the problem, we have to figure out what y is when x equals zero, and vice versa.
We can just plug in zero for x in the equation, to get 2 times zero, which is zero…
minus 7y equals 14.
Divide both sides by negative 7 and we get y equals negative 2.
Yeah, we didn’t HAVE to do that part to answer the question but it can’t hurt to
know for future reference.
Now we can plug in 0 for y to get 2x minus 7 times zero, which is 0, equals 14…
…so 2x equals 14. Now divide both sides by 2 and x equals 7.
The line crosses the x axis when x equals 7…
…and so our answer is D. Done.