Answer:
-613/716.
Step-by-step explanation:
The reciprocal of a number is basically that number upside down. to find the reciprocal of a whole number, you can just turn the number into a fraction, and put one as the numerator, and the original number as the denominator. given this information we know that the reciprocal of -716 is -1/716, so now yoj can simply cross multiply 613 by -1/716, which gives you -613/716.
A(t) = Ao*e^(-rt)
-rt = ln [ A(t)/ Ao]
t = - ln [ A(t)/ Ao] / r
r= 0.0124% = 0.0124/100 = 0.000124
A(t)/A0 = 10% = 10/100 = 0.1
Now substitute
t = - ln [0.1] / 0.000124 = 2.3025851 / 0.000124 = 18,569 years
Your result will depend on how you round ln(0.1).
prime factoring, oddly enough, is simply dividing by primes, anyhow, without much adieu.
36 = 2 * 2 * 3 * 3.
but anyway, prime factoring, is dividing by first 2, till you can't, then 3 till you can't, then 5 till you can't, and so on, and that plucks out all possible factors on any number.
174.97$ is the answer.
How I did it:
419.92 / 2.4 = 174.966 which rounds to 174.97$
