Question

Prove any one of the three identities: 1. (a + b)² = a² + 2ab + b² 2. (a - b)² = a² - 2ab + b² 3. a² - b² = (a + b) (a – b)

Answer 1

Answer:

1- (a+b)²=(a+b) (a+b)

=a(a+b)+b(a+b)

=a²+ab+ba+b²

=a²+2ab+b² (proved)