Evaluate -x + 8 for x = 5.

In this problem, you have to use substitution!

-x + 8, when x = 5

1) Substitute the value of 'x' with '5'

   -x + 8

= -5 + 8

2) Reverse the expression to make it easier to solve [optional]

  -5 + 8

= 8 - 5

3) Solve!

   8 - 5

= 3

Your answer is 3

I hope this helps!

- sincerelynini

hello,

as we don't know if g(x) is continue,

answer b

f(x)=2x²-8x+1=2(x²-4x+4)+1-8=2(x-2)²-7

vertex is (2,-7) ( a minimum since coefficient of x² is > 0)