Question 1135377
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Do I replace the (x) with 15? 
g(x) = -2x -3 
Find x if g(x) = 15
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Read the function definition and the question again.  The meaning is clear.



Do you replace x with 15?
Why?


What if you did?
{{{g(15)=-2*15-3=-30-3}}}, but "Find x if g(x) = 15", means something else.   Do you see?


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{{{g(x)=15=-2x-3}}}
{{{-2x-3=15}}}
{{{-2x=18}}}
{{{x=18/(-2)}}}
{{{highlight(x=-9)}}}