Question

find the product (3x+9 )square using the identity

Answer 1

Heya !! ☺

As we know, (a+b)² = a²+2ab+b²

So, (3x+9)²

=> 9x²+54x+81

=> x²+6x+9

=> x²+3x+3x+9

=> x(x+3)+3(x+3)

=> (x+3) (x+3)

=> x = -3

Answer 2

Heya ☺

(3x+9)^2

We use this identity

(a+b)^2 = a^2 + b^2 + 2ab

(3x+9)^2

= (3x)^2 + (9)^2 + 2 × 3x × 9

= 9x^2 + 81 + 54x

Again we use this identity

(a+b)^2 = a^2 + b^2 + 2ab

9x^2 + 81 + 54

= (3x)^2 + (9)^2 + 2 × 3x × 9

= (3x+9) (3x+9)


Thanks