Question

ਜੇਕਰ a ਅਤੇ b ਦੋ ਪੂਰਨ ਸੰਖਿਆਵਾਂ ਹੋਣ, ਤਾਂ ਹੇਠ ਲਿਖਿਆਂ ਵਿੱਚੋਂ ਕਿਹੜਾ ਕਥਨ ਸਹੀ ਨਹੀਂ ਹੈ? If a and b are two whole numbers, then which of the following statement is not correct? यदि a और b दो पूर्ण संख्याएँ हैं, तो निम्नलिखित में से कौन सा कथन सही नहीं है? *

a+b=b+a

ab=ba

a-b=b-a

none of these(ਇਹਨਾਂ ਵਿੱਚੋਂ ਕੋਈ ਨਹੀ)( इनमें से कोई नहीं)

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Answer 1

a-b = b-a is untrue as subtraction is non-commutative

Explanation:

We know that in Maths, addition and multiplication are commutative. Commutative means that changing the order of the operands does not change the result of the operation.

4 + 3 = 3 + 4 =7

4 * 3 = 3 * 4 = 12

But, subtraction is not commutative. Changing the order of operands will change the result of subtraction.

4 - 3 = 1

while 3 -4 = -1. They are not equal.

So a-b = b-a is not correct.

Answer 2

Explanation:

Among the various options given in question statement the correct option is option third.

a-b = b-a is not equal because of the sign factor in the answer. the magnitude or the value would be equal in both cases, but the sign would be different in both cases. Hence the commutative principle does not remain valid for this subtraction rule. In this case, the order of a and b will make the net result different