Question

Разложите на множители: 1) с^2-9 2) 25-n^2

Answer 1

$x^{2} - 9 = (c+3)(c-3)$ 
$25-n^{2} = (5-n)(5+n)$

Answer 2

1) с^2-9=(c-3)(c+3)
2) 25-n^2=(5-n)(5+n)