CAHSEE Math 3.3 Algebra I

Algebra I Drill 3 Problem 3. What is the x-intercept of the equation?

AlgebraCoordinates and Graphs
Algebra Ix- and y-intercepts
CAHSEE MathAlgebra I
LanguageEnglish Language
Systems of EquationsGraphing

Transcript

00:22

That is, the x intercept is where the line crosses the x axis like… here… and the

00:28

y axis is where it crosses… yes, shocker… the Y axis… here.

00:34

So to solve the problem, we have to figure out what y is when x equals zero, and vice versa.

00:40

We can just plug in zero for x in the equation, to get 2 times zero, which is zero…

00:45

minus 7y equals 14.

00:48

Divide both sides by negative 7 and we get y equals negative 2.

00:52

Yeah, we didn’t HAVE to do that part to answer the question but it can’t hurt to

00:56

know for future reference.

00:57

Now we can plug in 0 for y to get 2x minus 7 times zero, which is 0, equals 14…

01:06

…so 2x equals 14. Now divide both sides by 2 and x equals 7.

01:13

The line crosses the x axis when x equals 7…

01:16

…and so our answer is D. Done.