Q61Written answer
The reciprocal of a non-zero rational number q/p is the rational number q/p.
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Solution:-
False.
Reciprocal of non-zero rational number q/p is p/q.
NCERT Exemplar · Class 8 · Maths
Chapter 1: Rational Numbers
Practice each question, then open the answer or worked solution.
Questions
152 questionsQ62Written answer
If x + y = 0, then –y is known as the negative of x, where x and y are rational numbers.
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Solution:-
False.
If x and y are rational numbers, then y is known as the negative of x
Q63Written answer
The negative of the negative of any rational number is the number itself.
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Solution:-
True.
Let y be a positive rational number.
Then,
The negative of the negative of y is = – (- y)
= y
Q64Written answer
The negative of 0 does not exist.
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Solution:-
True.
Q65Written answer
The negative of 1 is 1 itself.
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Solution:-
False.
The negative of 1 = -1
Q66Written answer
For all rational numbers x and y, x – y = y – x.
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Solution:-
False.
Let x = 2, y = 3
Then,
LHS = x – y
= 2 – 3
= -1
RHS = y – x
= 3 – 2
= 1
By comparing LHS and RHS
-1 ≠ 1
LHS ≠ RHS
Q67Written answer
For all rational numbers x and y, (x) × (y) = (y) × (x)
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Solution:-
True.
Let x = 2, y = 3
Then,
LHS = 2 × 3
= 6
RHS = 3 × 2
= 6
By comparing LHS and RHS
6 = 6
LHS = RHS
Q68Written answer
For every rational number x, x × 0 = x.
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Solution:-
False.
Let x = 2
Then,
For every rational number x
(x) × (0) = 0
2 × 0 = 0
Q69Written answer
For every rational numbers x, y and z, x + (y × z) = (x + y) × (x + z).
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Solution:-
False.
For every rational numbers a, b and c, [a × (b + c) = (a × b) + (a × c)]
Q70Written answer
For all rational numbers a, b and c, a (b + c) = ab + bc.
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Solution:-
False.
Because, for every rational numbers a, b and c, [a × (b + c) = (a × b) + (a × c)]