Question

Use identity to solve:(a) (x-9) (x+10)

Answer 1

Answer:

use the identity (x+a)(x+b)=x^2+ (a+b)x+ab

Step-by-step explanation:

so lets evaluate it....

=(x-9)(x+10)

=x^{2} + (-9+10)x + (10)(-9)

=x^{2} +1x -90