Question

evaluate $f(x) = 5^{x - 1} - 6$ when $x = 9$. a 390,619 b 390,625 c 1,953,119 d 9,765,619

Explanation:

Step1: Substitute $x=9$ into the function

$f(9) = 5^{9-1} - 6$

Step2: Simplify the exponent

$9-1=8$, so $f(9) = 5^8 - 6$

Step3: Calculate $5^8$

$5^8 = 5\times5\times5\times5\times5\times5\times5\times5 = 390625$

Step4: Subtract 6 from the result

$f(9) = 390625 - 6$

Answer:

A. 390,619