Question

Factorise
400x^2-49y^2

Answer 1

(20x - 7y)(20x + 7y).

Explanation:

This is the difference of 2 squares;

a^2 - b^2 = (a - b)(a + b). So:

400x^2-49y^2

= (20x - 7y)(20x + 7y).

Answer 2

(20x + 7y) (20x - 7y)

Explanation:

400x²-49y² = (20x + 7y) (20x - 7y)