Real Numbers, Exponents, Scientific Notation and Roots Review 9 1. Write − 15 as a decimal. Name: _______________________ Date: _______ Color: ________ ̅̅̅ as a fraction in 2. Write 0. ̅75 simplest form. Simplify the expression. The simplified expression should have no negative exponents. 3. 43 × 45 4. (23 )4 5. (−6𝑎)3 6. (4𝑥𝑦 2 )2 7. 5(5−3 ) 8. (3)−3 9. (−3𝑥 2 𝑦)−2 (2−2 𝑥𝑦 −3 )2 11. 𝑥 3 𝑦 −5 2 10. 12. 6𝑥 4 𝑦 3 5𝑥𝑦 2 25𝑥 5 𝑦 3 ∗ −3𝑥 3 𝑦 7 4 3𝑥 −5 𝑦 −6 Rewrite the number in standard form. 13. 6.15 x 105 14. 1.4 x 10-6 Rewrite the number in scientific notation. 15. 0.000647 16. 54,900,000 Solve. Write your answer in scientific notation. 4.5 × 10−3 17. (3.1 x 10-2) x (9.6 x 106) 18. 19. (5.62 x 105) – (5.3 x 105) 20. (6.4 x 104) + (5.92 x 106) 5 × 10−5 21. Recently in the United States, there were 300,000,000 cell phone users. That same year, there were 5.7 x 109 cell phone users worldwide. About how many times larger was the number of cell phone users worldwide than in the United States? 22. In 2010, the population of a city was 100,000. Then each year for the next five years, the population increased by 3%. Write the exponential model that represents this situation. 23. You buy a used truck for $12,000. It depreciates at the rate of 18% per year. Write the exponential model that represents this situation. Classify the model as exponential growth or exponential decay. Identify the growth or decay factor and the percent of increase or decrease per time period. 24. 𝑦 = 17(1.9)𝑥 25. 𝑦 = 22(0.8)𝑥 26. 21. What is the value of the expression 144 −√100 22. To the nearest whole number, what is the best estimate of √214 23. The area of a square sandbox is 83 square feet. To the nearest foot, what is the perimeter of the sandbox? 24. What is the value of √216? 3 30. Estimate √130 to the nearest whole number. 3 25. Solve the equation 𝑥 2 = 400.