Question

factorise
(a-b)^2-49

Answer 1

Here we can see

49 = 7²


And we are given to factorise

(a - b)² - 7²

Let's assume that (a - b) = c


So we are left with,

(c)² - 7²


Can you remember any identity for this?

a² - b² = (a + b)(a - b)

That's it!

So,

c² - 7²

= (c + 7)(c - 7)

But we have assumed that c = a - b

So let's put c as a - b


(a - b + 7)(a - b - 7)


So we can say your answer is


(a - b + 7)(a - b - 7)


Hope it helps dear friend ☺️✌️