SOLUTION: Given g(x)= -12x-5 Find g^-1(-5)

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Question 1191153: Given g(x)= -12x-5
Find g^-1(-5)
Found 2 solutions by MathLover1, ikleyn:
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

Given g%28x%29=+-12x-5
Find g%5E-1%28-5%29
first find g%5E-1%28x%29
g%28x%29=+y
y=+-12x-5.....swap variables
x=+-12y-5......solve for+y
12y=+-x-5
y=+%28-x-5%29%2F12
g%5E-1%28x%29=+%28-x-5%29%2F12.......substitute -5 for x
g%5E-1%28-5%29=+%28-%28-5%29-5%29%2F12
g%5E-1%28-5%29=+%285-5%29%2F12
g%5E-1%28-5%29=+0%2F12
g%5E-1%28-5%29=+0


Answer by ikleyn(52778) About Me  (Show Source):
You can put this solution on YOUR website!
.
Given g(x)= -12x-5
Find g^-1(-5)
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            To answer the question, you do not need to express the function   g^(-1)(x)   explicitly:  it is an excessive unnecessary work.

            What you really need is to solve equation  g(x) = -5  and find  x.

            It is just enough and can be done in couple of lines. 


To answer the question, you need to solve equation g(x) = 5,  which is

    12x - 5 = -5   and implies   12x = 0,   x = 0.    


ANSWER.  x= 0.

Solved.