Write a recursive rule an explicit rule for the arithmetic sequence 15,22.5,30,37.5

The general expression is:

Step-by-step explanation:

For this case we have the following arithmetic sequence given:

15, 22.5, 30,37.5

In order to fidn the recursive rule for this sequence we need to take in count that the general formula for an arithmetic sequence is given by:

Where is the nth term the initial value for the sequence and d the common difference. For this case we have that

And for the first term we have:

For the second term we have this:

And solving for the value of d we got:

And for the 3th term we have:

And for the 4th term

So then our expression is correct and would be given by:

mr. flanders’ class sold 47 doughnuts and   mr. rodriquez’s class sold 38 cartons of milk

step-by-step explanation:

let x be the number of doughnuts sold by mr. flanders’ class and y be the number of cartons sold by mr. rodriquez’s class.

1. together, the classes sold 85 items, then

x+y=85.

2. both classes earn earned $104.49 for their school. if doughnuts were sold for $1.35 each, then x doughnuts costed $1.35x. if cartons of milk were sold for $1.08 each, then y cartons costed $1.08y. hence,

1.35x+1.08y=104.49.

3. solve the system of two equations: