Graphing and inverse

[mathmarauder]

im lost here. I need to find the inverse of f(x)
x-3 = 2/5 y
now i thought you multiply the denominator to get rid of the fraction
x-15 = 2y
x-15/2 = y
first of all is that correct?
Secondly how do you graph that?
i realize you probably dont have a graph utility in the response, but i have a blank graph here in
front of me and can piece it together with an explanation.

 

[arthur ohlsten]

graph and find inverse.
1) graph
x-3=2/5 y
clear fraction or multiply both sides by 5/2
5/2 x -15/2=y rewrite in form of y=mx+b a straight line

y= [5/2]x -15/2 a straight line , slope 5/2 , y intercept -15/2 , x intercept 3

graph the above

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find inverse

to find inverse of f[x] replace x with y and y with x
y= 5/2 x -15/2

inverse x=5/2 y -15/2
5/2 y= x + 15/2 multiply by 2/5
y= 2/5 x +3 answer

Arthur
please check math

 

[mathmarauder]

Thank you

 

[Denis]

x-15 = 2y
x-15/2 = y
first of all is that correct?

NO! (x - 15) / 2 = y : brackets are REQUIRED :shock:

 

[mathmarauder]

Thank you for the help