Question

the subtraction of rational numbers is not always dash and dash.

Answer 1

Heya!!!☺


Rational numbers are not always commutative and associative...

Hope this helps u ☺

Answer 2

Answer: The answer is associative and commutative.

Step-by-step explanation:  We are to write the two properties that are not satisfied by the subtraction of rational numbers.

(A) The first one is ASSOCIATIVITY.

If a, b and c are any three rational numbers, then the following property may not hold:

$(a-b)-c=a-(b-c).$

For example, let a =7, b =5  and  c = 2.

Then,

$(a-b)-c=(7-5)-2=2-2=0,\\a-(b-c)=7-(5-2)=7-3=4.$

Therefore, $(a-b)-c\neq a-(b-c).$

(B) The second property is COMMUTATIVITY.

If a and b are any three rational numbers, then the following property may not hold:

$a-b=b-a.$

For example, let a =7 and b =5.

Then,

$a-b=7-5=2,\\b-a=5-7=-2.$

Thus,

$a-b\neq b-a.$

Hence, associativity and commutativity are the two properties.