SOLUTION: The given function is {{{f(x)=20000-15x}}} Find {{{f^(-1)(50)}}}

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Question 128590: The given function is f%28x%29=20000-15x


Find f%5E%28-1%29%2850%29
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
f%28x%29=20000-15x Start with the given function


To find f%5E%28-1%29%28x%29, simply swap x and f(x) to get

x=20000-15f%28x%29


15f%28x%29%2Bx=20000 Add 15f(x) to both sides


15f%28x%29=20000-x Subtract x from both sides


f%28x%29=%2820000-x%29%2F15 Divide both sides by 15 to isolate f(x)


So the inverse function is f%5E%28-1%29%28x%29=%2820000-x%29%2F15


f%5E%28-1%29%2850%29=%2820000-50%29%2F15 Now plug in x=50


f%5E%28-1%29%2850%29=%2819950%29%2F15 Subtract


f%5E%28-1%29%2850%29=1330 Divide