tailieunhanh - Awa practise 6

Tham khảo tài liệu 'awa practise 6', ngoại ngữ, anh ngữ phổ thông phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | ------------------------------------ QUANTITATIVE PRETEST ------------------------------------------------ 4. b. Since the distance given is out of 40 minutes instead of 60 convert each distance to hours by using a proportion. For Diane use 25 60. Cross-multiply to get 40x 150. Divide each side by 40. Diane TATollrc 7 in Kaiii Quo rho comp tvrArỡcc 11C1TÌÍT -x- T cc_T mi1í ÌT ilA7 ÍT iTof- warKs 5 rrnres in one rrour. For Sue repeat ure same process using 40 60 . C ross murLipry Lo get 40x 90 and divide each side by 40. So Sue walks miles in one hour. . Diane walks miles per hour faster than Sue. 5. a. Factor the expression and cancel out common factors. 5x2 - 20 x - 42 x 221x- 22 x - 2 2 The exr ression reduces to x - 2. 5x 10 51x 2 2 51x 2 2 -x z lleexpresslOllreuucesLO x . 6. e. Translate the sentence into mathematical symbols and use an equation. Five less than y becomes y 5 and six more than x 1 becomes x 1 6. Putting both statements together results in the equation y 5 x 1 6. This simplifies to y 5 x 7. Since you need to find how much is x less than y solve the equation for x by subtracting 7 from both sides. Since x y 12 x is 12 less than y which is choice e. 7. c. Substitution can make this type of problem easier. Assume that you are buying 10 dozen eggs. If this 10 dozen eggs cost 20 then 1 dozen eggs cost 2. This is the result of dividing 20 by 10 which in this problem is x .If x is the cost of 1 dozen eggs then if you buy z dozen eggs the cost is x x z which is the same as choice c C y. 8. b. Use the proportion for the percent of change. 638 580 58 students is the increase in the number of students. 580 . Cross-multiply to get 580x 5 800 and divide each side by 580. x 10. 580 100 r 1 o 2 1 Therefore the percent of increase is 10 . The only statement that does not support this is b because it implies that fewer students are taking biology this year. 9. d. Let x the smaller integer and let y the larger integer. The first .