1. In 2010, there were about 4 x people living in California and about 1 x people living in Rhode Island. How many times larger was the population of California than the population of Rhode Island? 2. What value of x makes the equation below true?
9x - 15 - 2x = 3(-20 + 3x)

3. Solve the equation. Show all your work.
-3.5 (10x - 2) = -176.75

4. What values of a and b would make the equation shown have infinitely many solutions? 3x = ax + b
(multiple choice)
- a = 3
- a = anything but 3
- a = 0
- b = 3
- b = anything but 3
- b = 0

5. Mars has two moons, Phobos and Deimos. Phobos has a mass of 1.07 x kilograms and Deimos has a mass of 1.5 x kilograms. What is the total mass of the moons of Mars? Write your answer in scientific notation.

6. How many solutions does the equation -10x + 35 + 5x = -5x + 20 have?
- no solution
- one solution
- infinitely many solutions

7. Solve the equation. Show all your work.
−4(2x + 9) + 3x = 6 − 4(x − 3)

8. What is the value of the expression: x x x

9. Explain why 3(x + 4) = 3(x - 5) has no solution. Choose the best response below.
A. The coefficients of x are the same, but the constant terms are different.
B. The coefficients of x are different, but the constant terms are the same.
C. The coefficients of x are the same, and the constant terms are the same.
D. The coefficients of x are different, and the constant terms are different.

10. An atom of hydrogen has a mass of about 1.66 x grams. An atom of oxygen has a mass of about 2.656 x grams. How many times the mass of the hydrogen atom is the mass of the oxygen atom? Give your answer in scientific notation.

11. Which of these correctly describes the solution(s) to the equation shown below?
7x + 24 = 2x - 6
A. The equation has no solution.
B. The equation has infinitely many solutions.
C. The equation has one solution, which is x = 5.
D. The equation has one solution, which is x = -5.

12. Simplify the expression below. Write your answer in scientific notation.