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What are the slopes of the perpendicular lines?

1: y=-5/2x-8
2: y=5x
3: y=3x-8

User Kuba Suder
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2 Answers

4 votes

Answer:

1. 2/5

2. -1/5

3. -1/3

Step-by-step explanation:

the parpendicular slope is found by taking the original slope and finding the opposite reciprocal. so just flip the slope and make it the opposite sign

-5/2 ---> 2/5

+5/1 ---> -1/5

+3/1 ---> -1/3

User S Haque
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3 votes
Answer:
1. 2/5
2. -1/5
3. -1/3

Step-by-step explanation:
There are two key concepts that we have to understand in order to answer this question:

1) The given equations are organized in slope-intercept form: y=mx+b. Here’s what the variables mean:

Y= the y coordinate
M=the slope
X= the coordinate
B= the y intercept

From the given equations we can now identify the slopes as -5/2, 5 and 3.

2) Perpendicular lines have slopes that are NEGATIVE RECIPROCALS of each other.

Example: Line A has the slope 8. A line that is perpendicular to line A would have a slope of -1/8.

Example #2: Line B has the slope -2/3. A line that is perpendicular to line B would have a slope of 3/2 (two negatives make a positive).

Now that we understand these two concepts, we need to look at the slopes of the given lines and determine their negative reciprocals to find the slopes of their perpendicular lines.

1. y=-5/2x-8
We can see that -5/2 is in the place of “m” in y=mx+b. The negative reciprocal of -5/2 is 2/5, so therefore, the slope of the line perpendicular to y=-5/2x-8 is 2/5.

2. y=5x
There is no “b” value in this equation, but we can still identify 5 as “m”. The negative reciprocal of 5 is -1/5, so therefore, the slope of the line perpendicular to y=5c is -1/5.

3. y=3x-8
The negative reciprocal of 3 is -1/3, so therefore, the slope of the line perpendicular to line y=3x-8 is -1/3.

I hope this helps! Please comment if you have any questions.
User Sdicola
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