<span>Amanda has 26 nickels and dimes.
We shall call nickels x and dimes y.
We can write the following equations:
x = 3y -2 or -x +3y = 2
x + y = 26
We can cancel out the x to give 4y = 28 or y = 7
If there are 26 coins in total and 7 of them are dimes then there must be 19 nickels.
The number of nickels (19) is two fewer than three times the number of dimes ( 3(7) - 2 = 19).</span>
Answer:
Step-by-step explanation:
D
Answer:
The formula to determine the population of penguins at the end of the 7th year is:

Step-by-step explanation:
With this information, we know that the initial population at end of year 0 is 1000 penguins.
The first year will born 500 chicks (50% of the population) and also 20% of the total population will die.
We can then model the population for the end of year 1 as:

As this dynamic will continue with the years, we can generalize as:

Then, the value of the population at the end of the 7th year should be:

They could have assembled total 336 different possible crews.
<em><u>Explanation</u></em>
Total number of trained pilots is 9 and geologists is 4.
The crew should be consisted of 2 pilots and 1 geologist. That means, <u>2 pilots are chosen from total 9 and 1 geologist is chosen from total 4</u>.
Number of ways for choosing 2 pilots from 9
and
Number of ways for choosing 1 geologist from 4 
So, the total possible number of different crews they could have assembled 