The sales of homes in a new development have been increasing. in january, 5 homes were sold, in february, 12 homes were sold. in march, 19 homes were sold. this pattern continued for the remainder of the year. what is the explicit rule that can be used to find the number of homes sold in the nth month of the year? an=7n+5 an=7n+2 an=7n−5 an=7n−2

Answer

an=7n−2

Explanation

In January, 5 homes were sold, in February, 12 homes were sold. In March, 19 homes were sold.

The pattern formed is;

5, 12, 19

12 - 5  = 7

19 - 12 = 7

This shows that, the pattern is an arithmetic progressive.

Testing the rules give from the choices, the correct one is an=7n−2

1st term

5 = 7n−2

     (7×1) - 2 = 5

     = 7-2

      = 5

2nd term

12 = 7n−2    

       (7×2) - 2

      = 14 - 2

     = 12

3rd term

19 = 7n−2

    = (7×3) - 2

     = 21 - 2

     = 19

So the correct rule is an=7n−2.

an=7n−2

Step-by-step explanation:

Just took it and it's right!

-18

step-by-step explanation:

because mean value defines that total sum value over total number of set

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional