Elementary Math Question

Question

The number of people y​ (in millions) who have a​ driver's license can be estimated by the linear equation y=2.1x+20 ​, where x is the number of years after 2000a. Use this equation to complete the ordered pair (9,0)

b. Write a sentence explaining the meaning of the ordered pair in part​ (a).

c. If this trend​ continues, predict the number of people with​ driver's licenses in 2020.

Question content area bottom

Part 1

a. Complete the ordered pair ​(Simplify your​ answer.)

Answer 1

Hi Janet!

This is a tricky question, but we can solve it! The first thing we need to do is replace the variable X with the x from the ordered pair. The ordered pair (x,y) shows that x is 9. With this information, we can replace X in the equation y=2.1x+20. Replacing x with 9 gives us the equation y=2.1(9)+20. Now we can solve for y.

y=2.1(9)+20

y=18.9+20

y=38.9

Part A: We have completed our ordered pair! It is (9, 38.9).

Part B: Our sentence could say something like, "Since x=9, the year is 2000+9. This is written as 2009."

Part C: We are now asked to change x from 9 to 20. So we would write our equation as y=2.1(20)+20. The next step is to solve our new equation.

y=2.1(20)+20

y=42+20

y=62

After solving the new equation, we can state that by the year 2020, sixty million people will have a driver's license.

I hope this helps! :-)