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Find the possible equation for the line that is perpendicular to the graph of 5x --3y = 12 if the two lines intersect at x=30

Please show work

User Guster
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1 Answer

4 votes

Answer:

y = -(5/3)x + 64

Explanation:

note: if you don't have desmos, I suggest using it cause it helps a lot with graphing

first rearrange 5x - 3y = 12 to get the y by itself (y = mx + b)

m = slope

b = constant

you can start with subtracting 5x by both sides

now you have -3y = 12 -5x

then divide -3 by both sides

y = (12 - 5x) / -3

you can separate it so you have 12/-3 and -5x/-3

12/-3 = -4 and -5x/-3 you can't really solve but you can get rid of the negatives since two negatives make a positive

you should now have y = -4 + (5/3)x

I like to write it as y = (5/3)x -4 cause its easier to understand

* I always check desmos to make sure I still have the same graph

* The way you flip the line on the graph is by making the slope negative

since we know (5/3) is our slope all we do is make it negative

so (5/3) changes to -(5/3)

* The end number of the equation is where the line sits on the x axis

The way to find this is to start at 30 where the original line intersects and move left over 3 and up 5 then continue until you reach the x axis

when we switch to the other equation we see it sits on 64 on the x axis

y = -(5/3)x + 64

User Jaycee
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7.3k points