SOLUTION: If f(x)=x^2-2x-7, find the following values: f(3) and f(-4)

Algebra ->  Linear-equations -> SOLUTION: If f(x)=x^2-2x-7, find the following values: f(3) and f(-4)      Log On


   

Question 153614: If f(x)=x^2-2x-7, find the following values: f(3) and f(-4)
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
# 1

f%28x%29=x%5E2-2x-7 Start with the given function.


f%283%29=%283%29%5E2-2%283%29-7 Plug in x=3.


f%283%29=9-2%283%29-7 Square 3 to get 9


f%283%29=9-6-7 Multiply -2 and 3 to get -6.


f%283%29=-4 Combine like terms.




# 2



f%28x%29=x%5E2-2x-7 Start with the given equation.


f%28-4%29=%28-4%29%5E2-2%28-4%29-7 Plug in x=-4.


f%28-4%29=16-2%28-4%29-7 Square -4 to get 16.


f%28-4%29=16%2B8-7 Multiply -2 and -4 to get 8.


f%28-4%29=17 Combine like terms.