Question 1: Verify commutativity of addition of rational numbers for each of the following pairs of rational numbers:
(i) 11/5 and 4/7
(ii) 4/9 and 7/1249 and 712
(iii) 3/5 and 2/15
(iv) 2/7 and 12/35
(v) 4 and 3/5
(vi) 4 and 4/7
Answer :Commutativity of the addition of rational numbers means that if a/b and c/d are two rational numbers, then a / b + c / d = / d + a / b .(i)
We have 11/5 and 4/7.
Hence verified.(ii)
We have 4/9 and 7/12.
Hence verified. (iii)
Hence verified. (iv)
Hence verified. (v)
We have 4 and 3/5.
Hence verified. (vi)
We have 4 and 4/7
Hence verified.
Question 2: Verify associativity of addition of rational numbers i.e., (x + y) + z = x + (y + z), when:
Answer : We have to verify that (x+y)+z = x+(y+z).
(i)
Hence verified. (ii)
Hence verified. (iii)
Hence verified. (iv)
Hence verified.
Question 3: Write the additive inverse of each of the following rational numbers:
Answer:
(i)Additive inverse is the negative of the given number.So, additive inverse of −2/17 is 2/17.
(ii) Additive inverse is the negative of the given number.So, additive inverse of 3/11 is 3/11.
(iii) Additive inverse is the negative of the given number.So, additive inverse of 17/5 is 17/5.
(iv) Additive inverse is the negative of the given number.So, additive inverse of 11/25 is 11/25.
Question 4: Write the negative (additive inverse) of each of the following:
(i) 2/525
(ii) 7/979
(iii) 16/13
(iv) 5/1
(v) 0
(vi) 1
(vii) −1
Answer : (i) Negative of −2/5 is 2/5.
(ii) Negative of 7/−9 is 7/9.
(iii) Negative of −16/13 is 16/13.
(iv) Negative of −5/1 is 5/1.
(v) Negative value of 0 is 0.
(vi) Negative of 1 is −1.
(vi) Negative of −1 is 1.
Question 5: Using commutativity and associativity of addition of rational numbers, express each of the following as a rational number:
Answer :
(i) We have:
= 24/15= 8/5
(ii) We have:
= 51/63= 17/21
(iii) We have:
= 37/15
(iv) We have:
= 86/63
Question 6: Rearrange suitably and find the sum in each of the following:
Answer : (i)
= 47/4
(ii)
= 77/18
(iii)
= 23/15
(iv)
= 25/104
(v)
= 3/5
(vi)
= 801/336
= 267/112
Use Code STAYHOME200 and get INR 200 additional OFF

Use Coupon Code 