Since (-1) + 1 = 1 + (- 1), we can say that addition is commutative.?

Question

1.true
2.false
3.both 1 and 2
4.neither 1 and 2

Answer 1

both 1 and 2

Answer 2

it depends on what exactly the question means. addition certainly is commutative, and the fact that (-1) + 1 = 1 + (- 1) is an illustration of this property. but (-1) + 1 = 1 + (- 1) doesn't prove that addition is commutative. you would need to know that a + b = b + a for *all* numbers a and b.

if we were to interpret the question as asking whether we can conclude that addition is commutative or not, then I would say that, since the statement "(-1) + 1 = 1 + (- 1)" is neither a counterexample nor a proof that addition is commutative, the answer would be 4.

Answer 3

Addition is commutative.

Subtraction can be made commutative by replacing the minus sign with a plus sign and converting the signs of the number:

Ex: 4-2 can be converted to 4+(-2)
This can be commuted to (-2)+4

Answer 4

No. Showing this is true only for -1 and 1 does not show it's commutative. You have to show that, for every real a and b, we have a + b = b + a.

Answer 5

addition and multiplication are both commutative. I did a lesson during last semester on the commutative property. the order of factors or addends doesn't matter. SUBTRACTION and DIVISION is NOT commutative.

Answer 6

addition is commutative, as is subtraction, multiplication, and division (well assuming real numbers)

so 1