Question

use the identity (x+a)(x+b)=x²+(a+b)x+ab to find the following products: (2ab+5)(2ab-9)​

Answer 1

Answer:

4a²b²-8ab-45

Step-by-step explanation:

(x+a)(x-b)=x²+(a-b)x-ab

(2ab+5)(2ab-9)=(2ab)²+(5-9)2ab-5×9

=4a²b²-4×2ab-5×9

=4a²b²-8ab-45

Ur identity is wrong according to your question