Question

d. Evaluate the product (a-1)(a+1) for a = -2​

Answer 1

Answer:

3

Step-by-step explanation:

(a-1)(a+1) =a^2 -1

(-2)^2 -1

= 3

Answer 2

Step-by-step explanation:

by using identity 3 ; (a+b)(a-b)= a²-b²

(a-1)(a+1)= a²-1²

putting a=-2

= (-2)²-1

= 4-1= 3