Exercise 1.1

1.Write down a pair of integers whose:

(a) sum is –7 :

(i) -3 + = −7

(ii) 5 + ()= −7

(b) difference is –10 :

(i) 3 − = −10

(ii) -5 − = −10

(c) sum is 0:

(i) 6 + ()= 0

(ii) -8 + = 0

2.

(a) Write a pair of negative integers whose difference gives 8 :

(i) -2 −() = 8

(b) Write a negative integer and a positive integer whose sum is –5 .

(i) + 2 = −5

(c) Write a negative integer and a positive integer whose difference is –3.

(i) -1 − = −3

3. In a quiz, team A scored – 40, 10, 0 and team B scored 10, 0, – 40 in three successive rounds. Which team scored more? Can we say that we can add integers in any order?

Instruction

4. Fill in the blanks to make the following statements true:

(i) (–5) + (– 8) = (– 8) + ().

(ii) –53 + = –53

(iii) 17 + () = 0

(iv) [13 + (– 12)] + () = 13 + [(–12) + (–7)].

(v) (– 4) + [15 + (–3)] = [– 4 + 15] + ().