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y=−4y=0x−4 |
and |
y=3y=0x+3 |
| Write each equation in slope-intercept form. |
y=0x−4 |
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y=0x+3 |
| Since there is no x term we write 0x. |
y=mx+b |
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y=mx+b |
| Identify the slope and y-intercept of both lines. |
m=0 |
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m=0 |
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y-intercept is (0, 4) |
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y-intercept is (0, 3) |
The lines have the same slope and different y-intercepts and so they are parallel.
There is another way you can look at this example. If you recognize right away from the equations that these are horizontal lines, you know their slopes are both 0. Since the horizontal lines cross the y-axis at y=−4 and at y=3, we know the y-intercepts are (0,−4) and (0,3). The lines have the same slope and different y-intercepts and so they are parallel.