SOLUTION: If f(x)= x^2 -2x+5, and g(x)= 1/1-1/x, then f(-1) + g(-1) is equal to?

Algebra ->  Functions -> SOLUTION: If f(x)= x^2 -2x+5, and g(x)= 1/1-1/x, then f(-1) + g(-1) is equal to?      Log On


   

Question 180749: If f(x)= x^2 -2x+5, and g(x)= 1/1-1/x, then f(-1) + g(-1) is equal to?
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
First, let's find f(-1):

f%28-1%29=x%5E2-2x%2B5 Start with the given function.


f%28-1%29=%28-1%29%5E2-2%28-1%29%2B5 Plug in x=-1.


f%28-1%29=1-2%28-1%29%2B5 Square -1 to get 1.


f%28-1%29=1%2B2%2B5 Multiply -2 and -1 to get 2.


f%28-1%29=8 Combine like terms.


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Now let's find g(-1):


g%28x%29=1%2F%281-1%2Fx%29 Start with the given function.


g%28-1%29=1%2F%281-1%2F%28-1%29%29 Plug in x=-1.


g%28-1%29=1%2F%281%2B1%29 Reduce


g%28-1%29=1%2F2 Add


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So f%28-1%29=8 and g%28-1%29=1%2F2


f%28-1%29%2Bg%28-1%29 Move back to the main problem


8%2B1%2F2 Plug in f%28-1%29=8 and g%28-1%29=1%2F2


16%2F2%2B1%2F2 Multiply 8 by 2%2F2


%2816%2B1%29%2F2 Combine the fractions.


17%2F2 Add


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Answer:


So f%28-1%29%2Bg%28-1%29=17%2F2