Question 75675
#1
To find f(-1) plug in -1 for every x
{{{f(-1) = 5(-1) - 4}}}
{{{f(-1) = -5 - 4}}}
{{{f(-1) = -9}}}



#2
{{{(x^2 - 4x + 1) - (-8x^2 + 2x - 6) - (x^2 + 3x - 5)}}}
{{{x^2 - 4x + 1 +8x^2 - 2x + 6 - x^2 - 3x + 5}}} Distribute the negatives of each parenthesis
{{{(x^2 + 8x^2 - x^2) +(- 4x - 2x - 3x) + (1 + 6 + 5)}}} Group like terms
{{{8x^2 - 9x + 12}}} Combine like terms. This is your simplified answer.