Question

Factorise 4y² – 28yz + 49z² – 25x²​

Answer 1

Answer:

(2y+7z-5x)(2y+7z-5x).

Step-by-step explanation:

4y²=(2y)²

49z²=(7z)²

25x²=(5x)²

Now,

(2y)²-2(2y)(7z)+(7z)²-(5x)²

By using formula, (a-b)²=a²-2ab+b²

(2y+7z)²-(5x)²

Now again by using formula, a²-b²=(a+b)(a-b)

(2y+7z-5x)(2y+7z+5x)

Answer 2

Answer:

4y² - 28yz + 49z² - 25x²

⇒ [(2y)² - 2(2y)(7z) + (7z)²] - (5x)²

⇒ (2y - 7z)² - (5x)²

⇒ (2y + 7z - 5x)²

⇒ (2y + 7z - 5x)(2y + 7z - 5x)

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Hope it helps you!!

:)