Factorise

(X -2y )^2 -16/49

recall that a^2 - b^2 = (a-b)(a+b)

To factorize the expression (X - 2y)^2 - 16/49, we can use the difference of squares formula.

The difference of squares formula states that for any two numbers a and b, the expression a^2 - b^2 can be factored as (a + b)(a - b).

Looking at our given expression, we notice that we have (X - 2y)^2 which is the same as (a^2), and we have 16/49 which is the same as (b^2).

So, we can rewrite our expression as follows:
(X - 2y)^2 - (4/7)^2

Using the formula for difference of squares, we can now factorize the expression:
[(X - 2y) + (4/7)][(X - 2y) - (4/7)]

Simplifying further, we have:
[(X - 2y) + (4/7)][(X - 2y) - (4/7)]

Now, we have factored the given expression.