EVENTS CONVENT HIGH SCHOOL
05/08/2021 CLASS- SESSION2021-22(SLOT-1)
Maths
Chapter-1
INTEGERS EXERCISE 1.2
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Que-1 Explanation
Question 1.Write down a pair of integers whose:
(a) sum is -7
(b) difference is -10
(c) sum is 0.
Solution:
(a) Let
us take a pair of integers -3 and -4.
∴ (-3) + (-4) = -3 – 4 = -7
(b) Let
us take a pair of integers -12 and -2
∴ (-12) – (-2) = -12 + 2 =
-10
(c) Let
us take a pair of integers -3 and 3
∴ (-3) + (3) = -3 + 3 = 0
Que-2 Explanation
Question 2.
(a) Write a pair of negative integers whose difference gives 8.
(b) Write a negative integer and positive integer whose sum is
-5.
(c) Write a negative integer and a positive integer whose
difference is -3.
Solution:
(a) Let
us have -2 and -10
∴ Difference = (-2) – (-10)
= -2 + 10 = 8
(b) Let
us have -7 and 2
∴ (-7) + (2) = -7 + 2 = -5
(c) Let
us have -2 and 1
∴ (-2) – (1) = – 2 – 1 = -3
Que-3 Explanation
Question 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 you say that
we can add integers in any order?
table
Solution:Total score of team
A = (-40)
+ (10) + (0) – -40 + 10 + 0 = -30
Total
score of team
B = 10 +
0 + (-40) = 10 + 0 – 40 – -30
∴ The scores of both the
teams are same i.e. -30.
Yes, we
can add the integers in any order.
Question 4.Fill in the blanks to make the following statements
true:
(i) -5 + (-8) – (-8) + (-5) [Commutative
law of additions]
(ii) -53
+ 0 = -53 [Additive Identity]
[Adding 0
to any integer, it gives the same value]
(iii) 17
+ (-17) = 0 [Additive inverse]
(iv) [13
+ (-12)] + (-7) =13 + [(-12) + (-7)] [Associative law of addition]
(v) (-4)
+ [15 + (-3)] – [-4 + 15] + (-3) [Associative law of addition]
