Question

Which of the following statements are true? Select all that apply.

1. for all real numbers A and B, A+B=B+A
2. for all real numbers A and B, AB=BA
3. for all real numbers A and B, A-B=B-A
4. for all real numbers A, B and C, (A+B) + C = A + (B+C)
5. for all real numbers A, B and C, (A-B) - C = A - (B-C)
6. for all real numbers A, B and C, A(B+C)= AB+AC

Answer 1

1. true
example:
2+3=3+2
5=5

2. true
example:
3*4=4*3
12=12

3. false
example:
6-3=3-6
3≠-3

4. true
example:
(4 + 3) + 2= 4 + (3 + 2)
7 + 2 = 4 + 5
9 = 9

5. false
example:
(9 - 6) - 3 = 9 - (6 - 3)
3 - 3 = 9 - 3
0 ≠ 6

6. true
example:
2(3+4)= 2*3+2*4
2 * 7 = 6 + 8
14 = 14