Читать книгу Basic Math & Pre-Algebra All-in-One For Dummies (+ Chapter Quizzes Online) - Mark Zegarelli - Страница 64

1 −1. Find the difference; the answer is negative because 9 is farther from 0 than 8 on the number line: .

2 6. Drop the negative sign: .

3 −4. Find the difference; the answer is negative because 6 is farther from 0 than 2 on the number line: .

4 −15. The signs are the same, so drop the negative signs and find the sum. The answer is negative: .

5 30. Drop the negative signs and multiply. The product is positive, because the signs are the same: .

6 −5. Drop the negative sign and divide. The answer is negative, because the signs are different: .

7 −1. Change the subtraction to addition and the negative 6 to +6. Then find the difference. The answer is negative, because the newly adjusted signs are different and 7 is farther from 0 than 6 on the number line: .

8 4. Find the difference. The result is positive, so applying the absolute value keeps it a positive answer: .

9 10. Find the difference, because the signs are different. The answer is positive, because 19 is farther from 0 on the number line: .

10 5. Drop the negative signs and divide. The answer is positive, because the signs are the same: .

11 0. Change the subtraction to addition and the second −1 to +1. Then find the difference: .

12 9. First, find the difference of the numbers in the absolute value symbols. The sign of the difference is negative because 13 is farther from 0 than 4 on the number line. Evaluating the absolute value gives you a positive result: .

13 −16. Drop the negative signs and find the sum of the two numbers. The answer is negative, because the signs are the same: .

14 8. Change the problem to addition and the negative 14 to a positive number. Then, because the signs are different, find the difference. The answer is positive because 14 is farther from 0 than 6 on the number line: .

15 −40. Drop the negative sign and multiply. The answer is negative, because the signs are different: .

16 1. Find the difference between the two numbers, because the signs are different. The answer is positive, because 8 is farther from 0 than 7 on the number line: .

17 5. First, find the difference. Then apply the absolute value operation: .

18 2. Change the subtraction to addition and the negative 4 to +4. Then find the difference, because the signs are different. The answer is positive, because 4 is farther from 0 than 2 on the number line: .

19 2. Find the difference, because the signs are different. The answer is positive, because 5 is farther from 0 than 3 on the number line: .

20 −119. Change the subtraction to addition and make the 62 a negative number. Ignore the signs when you add the two numbers with the same sign. The sum is negative, because the signs are the same: .

21 157. Change the problem to addition and the negative 84 to a positive number. Then, because the signs are different, find the sum: .

22 38. Find the difference, because the signs are different. The answer is positive, because 90 is farther from 0 on the number line: .

23 263. First, find the difference, and then apply the absolute value operation. The difference will be negative, because 330 is negative and it’s farther from 0 on the number line. The absolute value operation makes the result positive: .

24 143. Drop the negative signs and multiply. The answer is positive, because the signs are the same: .

25 −20. Drop the negative sign and divide. The answer is negative, because the signs are different: .

26 −48. Find the difference, because the signs are different. The answer is negative, because 72 is farther from 0 on the number line: .