An=a1+d(n-1)
an=nth term
a1=first term, when n=1
d=common differnce=amount each term increases by
n=which one
so
when n=1, an=40
so a1=40
it seems to increas by 7 each time
an=40+7(n-1)
explicit formula is expanded
an=40+7n-7
an=33+7n is the formula
the domain is natural numbers because you can't have the -3rd term or the 0th term or the 3.24th term
domain is natural numbers
the formula is

or
Answer:
The guard should be positioned at the safe
Step-by-step explanation:
The night watchmen should be positioned to guard whichever place gives the highest expected value to the thief.
The expected value of robbing the safe is:

The expected value of robbing the cash register is:

Therefore, the guard should be positioned at the safe since it yields a higher expected value to the thief in case he tries to rob it.
Their ages are 24 years old each.
Remark
One of the things you need to do is learn to read phrase by phrase.
What is the quotient of a number and 7? That meas you have a number, x, and it is divided by 7. What you do that the answer you get is the quotient.
x/7 is what you know so for. Now the first part says you take 12 away from that.
x/7 - 12 is what you have after doing that.
The result you get is - 2
x/7 - 12 = - 2 Add 12 to both sides
x/7 - 12 + 12 = - 2 + 12
x/7 = 10 Now multiply by 7
x = 10 *7
x = 70 <<< Answer the number is 70