Question

use suitable indentity to get each of the following product:
1) (3a-12) (3a-12)
2) x/2+3y/4) (x/2+3y/4)​

Answer 1

Answer:

1) 9a² + 144 -72a

2) x²/4 + 9y²/16 + 3xy/4

Step-by-step explanation:

1)

(3a-12)(3a-12)

= (3a-12)²

Using (x-y)² = x² + y² - 2xy

where x = 3a

y = 12

(3a-12)²

= (3a)² + 12² - 2(3a)(12)

= 9a² + 144 - 72a

2)

(x/2 + 3y/4)(x/2 + 3y/4)

= (x/2 + 3y/4)²

Using (a+b)² = a² + b² + 2ab

where a = x/2

b = 3y/4

(x/2 + 3y/4)²

= (x/2)² + (3y/4)² + 2(x/2)(3y/4)

= x²/4 + 9y²/16 +3xy/4

Answer 2

Step-by-step explanation:

1) (3a - 12) (3a-12)

= (3a - 12)²

= (3a)² - 2x3ax12 + (12)² [(a-b) = a² - 2ab + b²]

= 3a² - 72a + 144

2) (x/2 + 3y/4) ( x/2 + 3y/4)

= (x/2 + 3y/4)²

= (x/2)² + 2 X x/2 X 3y/4 + (3y/4)²

x²/4 + 3xy/4 + 9y²/19