Question

Evaluate by using suitable identity (4x-7y) (4x-7y) ​

Answer 1

Answer:

16x² + 49y² - 56xy

Step-by-step explanation:

identity used : $(a - b)^{2}$ = a² + b² - 2ab

(4x-7y) (4x-7y) ​

⇒ (4x-7y)²

⇒ (4x)² + (7y)² - 2(4x)(7y)

⇒ 16x² + 49y² - 56xy

Answer 2

(4x-7y)(4x-7y)=(4x-7y)^2

Let a be '4x'
and b be '7y'

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

Therefore,(4x-7y)^2 = (4x)^2 - 2[(4x)(7y)] + (7y)^2

= 16x^2 - 2(28xy) + 49y^2
= 16x^2 - 56xy + 49y^2


Hope this answer will help you