Question

7.
57.
The set of all integers under the operation
* defined by a * b = a + b + 1 is a group,
then 3- is
(A) -5
(B) 5
(C) 4
(D) -3​

Answer 1

Answer:

5

Step-by-step explanation:

The set of all integers under the operation

* defined by a * b = a + b + 1

a * b = a + b + 1

if We need to find  3 * - 1

a = 3

b = - 1

3 * - 1  = 3  + (-1)  + 1

=> 3 * - 1 =  3

if We need to find  3 *  1

a = 3

b = 1

3 * 1 = 3 + 1  + 1

=> 3 * 1 = 5