A bakery sells 4200 cookies in 2010. The bakery sells 5600 cookies in 2015. Write a linear model that represents the number y of cookies that the bakery sells x years after 2010.

y = 4,200 + 280x

Step-by-step explanation:

Number of cookies sold by the bakery in 2010 = 4,200

Number of cookies sold by the bakery in 2015 = 5,600

Let's write a linear model that represents the number y of cookies that the bakery sells x years after 2010.

Cookies = y

Years after 2010 = x

Ratio of cookies sold in 2015 = (Number of cookies sold by the bakery in 2015 - Number of cookies sold by the bakery in 2010) / 2015 - 2010

Replacing with the values we know:

Ratio of additional cookies sold = 5,600 - 4,200 / 2015 - 2010

Ratio of additional cookies sold = 1,400 / 5 = 280 per year

Now, we can write the linear model this way:

y = 4,200 + 280x