SOLUTION: This problem is from a hand out we were given in class on friday. I have spent all weekend trying to figure this one out, amd still havent gotten much of anywhere. I evaluated it l

Algebra ->  Rational-functions -> SOLUTION: This problem is from a hand out we were given in class on friday. I have spent all weekend trying to figure this one out, amd still havent gotten much of anywhere. I evaluated it l      Log On


   

Question 73158: This problem is from a hand out we were given in class on friday. I have spent all weekend trying to figure this one out, amd still havent gotten much of anywhere. I evaluated it like I normally do(solve for x) and got an anwser that was 26, but that isn't one of the anwsers the teacher gave us as an option. I think I am missing something.
The problem is:
Given f(x)=5x^2-3x+1, find f(-2)
The anwsers the teacher gave us as possible were:
A)-13
B)15
c)-25
D) 27
I figure I might be close with the 26, but still so far away ;( Help please!
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Just plug in -2 for x
f%28-2%29=5%28-2%29%5E2-3%28-2%29%2B1
f%28-2%29=5%284%29%2B6%2B1
f%28-2%29=5%284%29%2B6%2B1
f%28-2%29=27
In this case you're not solving for x, it's already given as x=-2. You're actually solving for f(x).