If a = 256 and b = 175 , show that a - b ≠ b - a .

Given that a = 256 and b = 175 . Where a and b are two whole numbers. Let us first find a - b . ⇒ a - b = 256 - 175 = 81 . Now let us find the value of b - a . ⇒ b - a = 175 - 256 = - 81 . But 81 ≠ - 81 . Therefore a - b ≠ b - a . Thus commutative property does not hold good for subtraction of whole numbers. Hence proved.

If a = 12 , b = 8 and c = 5 , show that a - b - c ≠ a - b - c .

Given that a = 12 , b = 8 and c = 5 . Where a , b and c are three whole numbers. Let us first find a - b - c First, subtract c from b and then subtract the result from a . ⇒ 12 - 8 - 5 = 12 - 3 = 9 . Now let us find a - b - c . First subtract b from a and then subtract c from the result obtained. ⇒ 12 - 8 - 5 = 4 - 5 = - 1 . ⇒ 9 ≠ - 1 Therefore, a - b - c ≠ a - b - c . Hence proved.