Question

Use a suitable identity to get each of the following products.

(i) (x + 3) (x + 3)

(ii) (3a – ½)(3a – ½)​

Answer 1

Answer:

Step-by-step explanation:

1) (x + 3) (x + 3)

= ( x + 3 )² [∵(a + b)² = a²+ 2ab + b² ]

= x² + 2 ( x ) ( 3 ) + ( 3 )²

= x² + 6x + 9 is the answer.

2)(3a - 1/2) ( 3a - 1/2)

= ( 3a - 1/2 )² [∵( a- b )² = a² - 2ab + b² ]

= ( 3a )² - 2 ( 3a ) ( 1/2 ) + ( 1/2 )²

= 9a² - 3a + 1/4 is the answer.

Answer 2

Answer:

(¡) (x+3)(x+3)

let a=x and b=3

= (x+3)²

we know that,

(a+b)²= (a²+b²+2ab)

(x+3)²=(x²+3²+2×x×3)

=x²+9+6x

(¡¡) (3a-1/2)(3a-1/2) (same as (¡)

we know that

(3a-1/2)(3a-1/2)=(3a-1/2)²

(3a-1/2)²={3a²+(1/2)²+2×3a×(-1/2)}

=9a²+1/4+6a×(-1/2)

=9a²+1/4-3a

Hope it's correct:)