Question

1). (a+b) (a-b). 2. (1-a) (1-b)​

Answer 1

Step-by-step explanation:

1.)(a+b) (a-b)= a²-b²

2.)(1-a) (1-b)= 1-b-a+ab

Answer 2

Step-by-step explanation:

ab

2

+(a−1)b−1

=ab

2

+ab−b−1

=ab(b+1)−1(b+1)

=(b+1)(ab−1)