4. Write the opposite of each of the following statements-
(i) Profit of 20 =
(ii) Increase of 100 =
(iii) Adding 4=
(iv) A depth of 10 m =
Answers
Step-by-step explanation:
(v) On the number line, we start from 0 and move 4 steps to the left to reach point A. Now, starting from A, we move 7 steps to the left to reach point B.
B represents the integer −11.
∴ (−4) + (−7) = −11
(vi) On the number line, we start from 0 and move 2 steps to the left to reach point A. Now, starting from A, we move 8 steps to the left to reach point B.
B represents the integer −10.
∴ (−2) + (−8) = −10
(vii) On the number line, we start from 0 and move 3 steps to the right to reach point A. Now, starting from A, we move 2 steps to the left to reach point B. Again, starting from B, we move 4 steps to the left to reach point C.
C represents the integer −3.
∴ 3 + (−2) + (−4) = −3
(viii) On the number line, we start from 0 and move 1 step to the left to reach point A. Now, starting from A, we move 2 steps to the left to reach point B. Again, starting from B, we move 3 steps to the left to reach point C.
C represents the integer −6.
∴ (−1) + (−2) + (−3) = −6
(ix) On the number line, we start from 0 and move 5 steps to the right to reach point A. Now, starting from A, we move 2 steps to the left to reach point B. Again, starting from B, we move 6 steps to the left to reach point C.
C represents the integer −3.
∴ 5 + (−2) + (−6) = −3
Page No 68:
Question 2:
Fill in the blanks:
(i) (−3) + (−9) = .......
(ii) (−7) + (−8) = .......
(iii) (−9) + 16 = .......
(iv) (−13) + 25 = .......
(v) 8 + (−17) = .......
(vi) 2 + (−12) = .......
ANSWER:
(i)
(−3) + (−9)
= −3 − 9
= −12
(ii)
(−7) + (−8)
= −7 − 8
= −15
(iii)
(−9) + 16
= −9 + 16
= 7
(iv)
(−13) + 25
= −13 + 25
= 12
(v)
8 + (−17)
= 8 − 17
= −9
(v)
2 + (−12)
= 2 − 12
= −10
Page No 68:
Question 3:
Add:
(i) −365 −87
(ii)−73 −687
(iii)−1065 −987
(iv) −3596 −1089
ANSWER:
(i)
−365 −87−452
−365
−365 −87 −365 −87-365 and -87 are both negative integers. So, we add 365 and 87, and put the negative sign before the sum.
(ii)
−687 −73−760
-687 and -73 are both negative integers. So, we add 365 and 87, and put the negative sign before the sum.
(iii)
−1065 −987−2052
-1065 and -987 are both negative integers. So, we add 1065 and 987, and put the negative sign before the sum.
(iv)
−3596−1089−4685
-3596 and -1089 are both negative integers. So, we add 3596 and 1089, and put the negative sign before the sum.
Page No 68:
Question 4:
Add:
(i) −206 +98