Bill bought 4 pens for $12. which of the following equations shows the relationship between the cost of pens, c, and the number of pens, x, bought? what will the cost of 20 pens be?
options:
c = 3x, $12
x = 3c, $60
c = 3x, $60
x = 3c, $12

The answer to your question is: c = 3x, $60

Step-by-step explanation:

Bill bought = 4 pens for $12

equation cost vs # of pens (x)

Cost of 20 pens?

                           4 pens $12

                            1 pen         x

                           x = 1(12)/4

                          x = 3

Equation :

            cost = 3x

20 pens will cost

           cost = 3(20)

                   = $60

Answer : c = 3x, $60