Question

evaluating functions
given the function, evaluate. be sure to use the order of operations!
$f(x) = 4x - 8$ $g(x) = -2x^2 - x + 7$ $k(x) = \frac{2}{5}(x + 1)$ $h(x) = 3^x - 4$ $b(x) = 8(x - 1)^2$

a. evaluate $g(8)$: $g(8) = \square$

b. evaluate $f(6)$ $f(6) = \square$

c. evaluate $k(4)$: $k(4) = \square$

d. evaluate $h(3)$ $h(3) = \square$

Explanation:

Step1: Substitute $x=8$ into $g(x)$

$g(8) = -2(8)^2 - 8 + 7$

Step2: Calculate exponents and multiply

$g(8) = -2(64) - 8 + 7 = -128 - 8 + 7$

Step3: Compute final value for $g(8)$

$g(8) = -129$

Step4: Substitute $x=6$ into $f(x)$

$f(6) = 4(6) - 8$

Step5: Multiply then subtract

$f(6) = 24 - 8 = 16$

Step6: Substitute $x=4$ into $k(x)$

$k(4) = \frac{2}{5}(4 + 1)$

Step7: Simplify inside parentheses then multiply

$k(4) = \frac{2}{5}(5) = 2$

Step8: Substitute $x=3$ into $h(x)$

$h(3) = 3^3 - 4$

Step9: Calculate exponent then subtract

$h(3) = 27 - 4 = 23$

Answer:

a. $g(8) = -129$
b. $f(6) = 16$
c. $k(4) = 2$
d. $h(3) = 23$