SOLUTION: If f(x) = 8x^3 + 5x^2 - x + C and f(-3) = 1, what is the value of C?

Algebra ->  Functions -> SOLUTION: If f(x) = 8x^3 + 5x^2 - x + C and f(-3) = 1, what is the value of C?       Log On


   

Question 656244: If f(x) = 8x^3 + 5x^2 - x + C and f(-3) = 1, what is the value of C?

Found 2 solutions by jim_thompson5910, josmiceli:
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
f(x) = 8x^3 + 5x^2 - x + C

f(-3) = 8(-3)^3 + 5(-3)^2 - (-3) + C

1 = 8(-3)^3 + 5(-3)^2 - (-3) + C

1 = 8(-27) + 5(9) - (-3) + C

1 = -216 + 45 + 3 + C

1 = -168 + C

1 + 168 = C

169 = C

C = 169

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+f%28x%29+=++8x%5E3+%2B+5x%5E2+-+x+%2B+C++
and f(-3) = 1
+f%28-3%29+=+8%2A%28-3%29%5E3+%2B+5%2A%28-3%29%5E2+-+%28-3%29+%2B+C++
+f%28-3%29+=+8%2A%28-27%29+%2B+5%2A9+%2B+3+%2B+C+
+f%28-3%29+=+-216++%2B+45+%2B+3+%2B+C+
+f%28-3%29+=+-168+%2B+C+
+-168+%2B+C+=+1+
+C+=+169+