SOLUTION: 3 2 Given f(x) = –x – 2x + 3x – 9, find f(–2), f(0), and f(1). I have been trying to work this out but do not know if I am working it correctly. Thanks ( Idid

Algebra ->  Linear-equations -> SOLUTION: 3 2 Given f(x) = –x – 2x + 3x – 9, find f(–2), f(0), and f(1). I have been trying to work this out but do not know if I am working it correctly. Thanks ( Idid       Log On


   

Question 123006: 3 2
Given f(x) = –x – 2x + 3x – 9, find f(–2), f(0), and f(1). I have been trying to work this out but do not know if I am working it correctly. Thanks
( Idid not know how to post it correctly but the three is supposed to be above the x and the 2 is supposed to be above the the y)
Found 2 solutions by checkley71, jim_thompson5910:
Answer by checkley71(8403) About Me  (Show Source):
You can put this solution on YOUR website!
Sorry but i don't see any y in this equation.
If you're trying to show powers then use x^2 which is x*x or x squared.

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

Let's evaluate f(-2)

f%28x%29=-x%5E3-2x%5E2%2B3x-9 Start with the given function


f%28-2%29=-%28-2%29%5E3-2%28-2%29%5E2%2B3%28-2%29-9 Plug in x=-2


f%28-2%29=-1%2A-8-2%2A-2%5E2%2B3%2A-2-9 Raise -2 to the 3rd power to get -8


f%28-2%29=8-2%2A-2%5E2%2B3%2A-2-9 Negate -8 to get 8


f%28-2%29=8-2%2A4%2B3%2A-2-9 Raise -2 to the 2nd power to get 4


f%28-2%29=8-8%2B3%2A-2-9 Multiply 2 and 4 to get 8


f%28-2%29=0%2B3%2A-2-9 Subtract 8 from 8 to get 0


f%28-2%29=0%2B-6-9 Multiply 3 and -2 to get -6


f%28-2%29=-6-9 Add 0 and -6 to get -6


f%28-2%29=-15 Subtract 9 from -6 to get -15




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Let's evaluate f(0)


f%28x%29=-x%5E3-2x%5E2%2B3x-9 Start with the given function


f%280%29=-1%280%29%5E3-2%280%29%5E2%2B3%280%29-9 Plug in x=0


f%280%29=0-2%2A0%5E2%2B3%2A0-9 Raise 0 to the 3rd power to get 0



f%280%29=0-2%2A0%2B3%2A0-9 Raise 0 to the 2nd power to get 0


f%280%29=0-0%2B3%2A0-9 Multiply 2 and 0 to get 0


f%280%29=0%2B3%2A0-9 Subtract 0 from 0 to get 0


f%280%29=0%2B0-9 Multiply 3 and 0 to get 0


f%280%29=0-9 Add 0 and 0 to get 0


f%280%29=-9 Subtract 9 from 0 to get -9




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Let's evaluate f(1)


f%28x%29=-x%5E3-2x%5E2%2B3x-9 Start with the given function


f%281%29=-%281%29%5E3-2%281%29%5E2%2B3%281%29-9 Plug in x=1


f%281%29=-1%2A1-2%2A1%5E2%2B3%2A1-9 Raise 1 to the 3rd power to get 1


f%281%29=-1-2%2A1%5E2%2B3%2A1-9 Negate 1 to get -1


f%281%29=-1-2%2A1%2B3%2A1-9 Raise 1 to the 2nd power to get 1


f%281%29=-1-2%2B3%2A1-9 Multiply 2 and 1 to get 2


f%281%29=-3%2B3%2A1-9 Subtract 2 from -1 to get -3


f%281%29=-3%2B3-9 Multiply 3 and 1 to get 3


f%281%29=0-9 Add -3 and 3 to get 0


f%281%29=-9 Subtract 9 from 0 to get -9