If 2 objects cost 40 dollars how much would 7 objets cost?

$140

Step-by-step explanation:

We can use a ratio to solve

2 objects         7 objects

=

$40                  x dollars

Using cross products

2 *x = 40 *7

2x = 280

Divide each side by 2

2x/2 =280/2

x = 140

7 objects cost 140 dollars

you need a common difference between consecutive terms to be constant, like 1,2,3,4 or 2,4,6,8, or 1,3,6,9