Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Middle Level Heading __________________________ Chapter 2 Study Guide Solve each equation. Check your answer. If the equation is an identity, write identity. If it has no real-number solution, write no solution. 1. 3n + 2 = –2n – 8 5n + 2 = -8 5n = -10 2. 1 3 z2 4 4 z+2=3 z=1 3. x4 5 6 4 x – 4 = 30/4 x = 11.5 n = -2 4. 8x – 12 = 4x + 24 4x – 12 = 24 4x = 36 x=9 6. 1 (d 12) 4 4 5. (3z + 4) = 6z 3(3z + 2) -3z – 4 = 6z – 9z - 6 -3z – 4 = -3z - 6 – 4 = -6 no solution 7.–5(5.25 + 3.1x) = –6.2(2.5x + 1.9) 1/4d – 3 = 4 -26.25 + (-15.5x) = -15.5x + -11.78 1/4d = 7 -26.25 = -11.78 d = 28 no solution Solve each equation. Justify your steps. 8. 8 + 3m = –7 3m = -15 m = -5 9. Subtraction Property of Equality Division Property of Equality 1 y 5 8 2 1/2y = 3 Subtraction Prop of Equality y=6 Multiplication Prop of Equality 10. A youth club is taking a field trip to a community farm. 27 members attended the trip. The total cost for the trip was $148.50. Write and solve an equation to determine the cost for each person. Equation $148.50 = 27x Solution $5.50 per person Solve each equation for the given variable. 11. –3ab – 2bc = 12; c 12. c f 2 d g -2bc = 12 + 3ab 12 3ab c 2b c f 2 d g c d( f 2) g Define a variable and write an equation for each situation. Then solve. 13. A large cheese pizza costs $7.50. Each additional topping for the pizza costs $1.35. If the total bill for the pizza Sally ordered was $12.90, how many toppings did she order? Define variable: x = number of toppings Solution: 4 toppings Equation: $12.90 = $7.50 + $1.35x 14. A water park offers a season pass for $64 per person, which includes free admission and free parking. Admission for the water park is $14.50 per person. Parking is normally $5 for those without a season pass. a. How many visits to the water park would you have to use for the season pass to be a better deal? Define variable: x = visits that make both deals equal Equation: 64 = 14.50x + 5x X = 3.28… Solution: You would have to visit the park 4 times to make the season pass a better deal. b. What would the total cost be for 3 visits with and without a season pass? With the season pass, the cost is $64. Without the season pass, the cost is $58.50. Convert the given amount to the given unit. 15. 60 ft; in 16. 3 mi; ft 17. 150 sec; min 720 inches 15,840 feet 2.5 minutes 18. A car went 25 miles per hour. What was the car’s average speed in feet per second? 25mi 1hr 5280 ft 132000 ft 36.6 ft 1hr 3600sec 1mi 3600sec 1sec 5 3 5 19. y 20. -3y = 25 15z = 72 15 8 9 z y=-25/3 y = 8 z = 72/15 1 3 10 z 8 4 16 21. 16(10) = 4(z-8) 160 = 4z – 32 4 z= 12 4 4 15 5 4d 1 3 d 9 2 22. -2(4d+1) = -3(d+9) -8d + (-2) = -3d + (-27) 192 = 4z -5d + (-2) = -27 48 = z -5d = -25 d=5 The figures are similar. Find the missing length. Round your answer to the nearest tenth. 23. m = _____________ 10 7 m 18 m = 25.7 24. You project a drawing 7 inches wide and 4 1 inches tall onto a wall. The projected image is 27 2 inches tall. How wide is the projected image? 7 4.5 x 27 x = 42 inches 25. What percent of 37 is 111? 26. What is 72% of 150? 111 = 37x 3=x x = 0.72(150) x = 108 27. 60% of what number is 102? 0.6(x) = 102 x = 170 300% Tell whether each percent change is an increase or decrease. Then find the percent change. Round to the nearest tenth of a percent. 28. Original amount: $27 New amount: $30 increase 29. Original amount: $250 New amount: $200 Decrease 30 27 3 0.1 11.1% 27 27 30. Original amount: 873 New amount: 781 decrease 250 200 50 0.2 20% 250 250 31. Original amount: 4.7 New amount: 6.2 increase 873 781 92 0.105... 10.5% 873 873 6.2 4.7 1.5 0.241... 31.9% 4.7 4.7 32. The scale on a map is 1 in : 25 mi. You measure 6.5 in. between two towns. What is the actual distance? 1in 6.5in 6.5(25) 1x 162.5miles 25mi x 33. In 1970, the U.S. population was about 205 million people. In 2007, it was about 301 million. What was the percent increase? Round your answer to the nearest tenth of a percent. 301 205 96 0.468... 46.8% 205 205 Find the percent error in the estimation. Round to the nearest percent. 34. You estimate that a tree is 45 feet tall. It is actually 58 feet tall. 45 58 13 0.224... 22.4% 58 58 35. Write a problem that can be solved using similar polygons. Draw a diagram and solve the problem. 36. Write a multi-step equation for each condition listed below. a. equation has no solution b. equation has one solution c. equation is an identity 37. The average class grade went from 79% to 85%. Your friend thinks this represents a 6% change in the average. Explain your friend’s error. What is the actual percent increase rounded to the nearest tenth percent? 85 79 6 0.075... 7.5% 79 79 The friend subtracted 79% from 85% to get 6%. The actual percent increase is calculated above to be 7.5%.