SOLUTION: I have these problems and in need of help . Please explane and help me . Thanks . For f(x) = 5x – 4, find f (-1). Perform the indicated operations: (x2 – 4x + 1) – (-

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: I have these problems and in need of help . Please explane and help me . Thanks . For f(x) = 5x – 4, find f (-1). Perform the indicated operations: (x2 – 4x + 1) – (-      Log On


   

Question 75675: I have these problems and in need of help . Please explane and help me . Thanks .

For f(x) = 5x – 4, find f (-1).

Perform the indicated operations:
(x2 – 4x + 1) – (-8x2 + 2x – 6) – (x2 + 3x – 5)

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
#1
To find f(-1) plug in -1 for every x
f%28-1%29+=+5%28-1%29+-+4
f%28-1%29+=+-5+-+4
f%28-1%29+=+-9


#2
%28x%5E2+-+4x+%2B+1%29+-+%28-8x%5E2+%2B+2x+-+6%29+-+%28x%5E2+%2B+3x+-+5%29
x%5E2+-+4x+%2B+1+%2B8x%5E2+-+2x+%2B+6+-+x%5E2+-+3x+%2B+5 Distribute the negatives of each parenthesis
%28x%5E2+%2B+8x%5E2+-+x%5E2%29+%2B%28-+4x+-+2x+-+3x%29+%2B+%281+%2B+6+%2B+5%29 Group like terms
8x%5E2+-+9x+%2B+12 Combine like terms. This is your simplified answer.