1. 2.1, 2.3, & 2.4 Writing and Solving Equations
Unit 1: September 4, 2014

2. The population of the United States in July 2007 was about 301,000,000, and the land area of the United States is about 3,500,000 square miles. Write an equation to find the average number of people in the US. Then solve!

3. Katie is twice as old as her sister Mara.
The area of the Hartstein’s kitchen is 182 square feet.
This is 20% of the area of the first floor of their house.
Let F represent the area of the first floor.
Write an equation to represent the situation. Then solve!
Katie is twice as old as her sister Mara.
The sum of their ages is 24. Write a one-variable
equation to represent the situation. Then solve!

4. Now what steps did you use in solving these equations?
INVERSE OPERATIONS!!!!!!

5. Try a Few! d – 8 = 17 2. v + 12 = –5 3. b – 2 = –11 4. –16 = m + 71
5. 29 = a – –14 + y = –2

6. Try another!
Kingda Ka in New Jersey is the tallest and fastest roller coaster in the world.
Riders travel at an average speed of 61 feet per second for 3118 feet. They
reach a maximum speed of 187 feet per second.
If x represents the total time that the roller coaster is in motion for each
ride, write an expression to represent the situation.
(Hint: Use the distance formula d = rt.)
b. How long is the roller coaster in motion?

7. Creating and Solving! Working for Apple after college, you work
In the production of headphones department.
For general expenditures, it cost 5,000,000 a month,
And for parts/production, the headphones cost $2.50
Per headphone. Create an equation to model the
Cost of Apple for the headphones.
a) If in the month of October, the total cost was 6.2 million,
how many headphones were produced?
b) How much should Apple charge for the headphones,
If Apple wants to have a revenue of 11.2 million?
c) What would the revenue be for Apple?

8. Try a Few
–12n – 19 = f = 14
3. 15t + 4 = 𝑢 = 2
5. 𝑑 − = 𝑏 3 – 6 = –2

9. More Word Problems
Supplementary angles are angles whose measures have a sum of 180º. Complementary angles are angles whose measures have a sum of 90º. Find the measure of an angle whose supplement is 10º more than twice its complement. Let 90 – x equal the degree measure of its complement and 180 – x equal the degree measure of its supplement. Write and solve an equation.

10. A few to try 1. 5 + 3r = 5r – 19 2. –9 + 8k = 7 + 4k
3. 8q + 12 = 4(3 + 2q) (5j + 2) = 2(3j – 6)