Question

The question is confusing....

Answer 1

`c=35r+10`

Explanation:

We need to create a linear equation in the form: c = mr + b

(where m is the slope and b is the y-intercept)

Choose two ordered pairs from the table: (2, 80) and (4, 150)

Let
`(r_1,c_1)` = (2, 80)

Let
`(r_2,c_2)` = (4, 150)

Calculate the rate of change (slope of linear equation) by dividing the change in c by the change in r:

`\textsf{slope} \ m=(c_2-c_1)/(r_2-r_1)=(150-80)/(4-2)=35`

Now use point-slope form of linear equation to create final equation:

`c-c_1=m(r-r_1)`

`\implies c-80=35(r-2)`

`\implies c=35r+10`