Question

Factorise y^2 - 169?????????????

Answer 1

Step 1. Rewrite it in the form: $a^{2} - b^{2}$, where a = y and b = 13

$y^{2} - 13^{2}$

Step 2. Use Difference of Squares: $a^{2} - b^{2} =(a+b)(a-b)$

$(y+13)(y-13)$

Done!

Answer 2

= y^2 - 169
= (y)^2 - (13)^2
= (y + 2)(y - 2)