Question

Factorise:
1 - 2ab - (a^2 + b^2) = ?
(a) (1 + a - b) (1 + a + b)
(b) (1 + a + b) (1 - a + b)
(c) (1 + a + b) (1 - a - b)
(d) (1 + a - b) (1 - a + b)​

Answer 1

1-2ab-a² -b²
1-(a+b)²
1² - (a+b)²
(1-a-b)(1+a+b)
C is correct