Carbon-14 has a half-life of approximately 5400 years
(a) find a function that gives the amount, a, of carbon-14 in an object after t years. (use the variable a to represent the initial amount).
(b) a leaf is found that contains 25% of the carbon-14 it originally had. approximately how old is it? (round your answer to the nearest year.)

answer: 21$

step-by-step explanation:

$42 / $14 = 3   (ratio 3: 1)

$7 x 3 = $21

which expression can be used to convert 80 us dollars (usd) to australian dollars (aud)?

1 usd = 1.0343 aud

1 aud = 0.9668 usd

step-by-step explanation:

sorry just need the points

none of the above.

for one of the equations to be used in the process, there has to be a term in the equation since squared is .

since there is only a term in the first equation, we cannot derive a from completing the square.

solving with completing the square