Question

Factorise the following expression.

2x² − 8y²

Answer 1

2x² − 8y²

= 2(x² − 4y²)

Let us recognize it as the difference of the squares of a and b.

a = x²

b = 4y² = 2y²

a² − b² = (a + b)(a − b)

= 2 [(x)² − (2y)²]

= 2 (x + 2y) (x − 2y)