question
- Thread starter BK94
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mmm4444bot
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x-intercepts are points that take this form: (x, 0).
I mean, all x-intercepts occur where y = 0.
Substitute 0 for y in your equation, and solve for x.
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y-intercepts are points that take this form: (0, y).
I mean, all y-intercepts occur where x = 0.
Substitute 0 for x in your equation, and solve for y.
Alternatively, you could recognize that the given equation is written in the Slope-Intercept form of a line. You can see the y-intercept, by inspection.
mmm4444bot
Super Moderator
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The instruction "substitute 0 for x in the equation" means to write this:
y = 2(0) + 4
Now, do the math.
y = 0 + 4
y = 4
The y-intercept is 4.
That means the line passes through the point (0, 4).
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Likewise, the x-intercept is the point where the line crosses the x-axis. The y-coordinate is zero, there. We substitute zero for y.
0 = 2x + 4
Solve for x means to get x by itself on one side.
Subtract 4 from both sides, to first isolate the term containing x.
0 - 4 = 2x + 4 - 4
Do the math.
-4 = 2x
Isolate x by dividing both sides by 2
-4/2 = 2x/2
Do the math
-2 = x
The x-intercept is -2.
That means the line passes through the point (-2, 0).