How do you evaluate the polynomial #-3x^3+8x^2-4x-6# for #x=4# and for #x=-4#?

1 Answer
Jun 24, 2018

#-86" and "330#

Explanation:

#"substitute the given values for x into the expression"#

#-3xx(color(red)(4))^3+8xx(color(red)(4))^2-4xxcolor(red)(4)-6#

#=(-3xx64)+(8xx16)+(-4xx4)-6#

#=-192+128-16-6#

#=-86#

#-3xx(color(red)(-4))^3+8xx(color(red)(-4))^2-4xxcolor(red)(-4)-6#

#=(-3xx-64)+(8xx16)+(-4xx-4)-6#

#=192+128+16-6#

#=330#