Answer:
A
Step-by-step explanation:
A is the only equation that does not account for the fact that Tu bought 2 tickets and 2 drinks.
The rest do: B subtracts the appropriate amounts twice, C multiplies the doubled expenses, and D does the same, just the amount paid is also separated.
Answer:
We can use the sample about 42 days.
Step-by-step explanation:
Decay Equation:



Integrating both sides


When t=0, N=
= initial amount




.......(1)
.........(2)
Logarithm:
130 days is the half-life of the given radioactive element.
For half life,
,
days.
we plug all values in equation (1)






We need to find the time when the sample remains 80% of its original.







We can use the sample about 42 days.
Answer:
32m + 24n
Step-by-step explanation:
Distribute the 8 to the other terms.
8(4m + 3n)
32m + 24n