Question

10. Factorise:
x2 - y2 - 2y - 1​

Answer 1

Its simple but you need see the method and steps takens twice if you don't understand. Refer the attachment for your answer.

Answer 2

Answer:

(x + y +1)(x - y - 1)

Step-by-step explanation:

${x}^{2} - {y}^{2} - 2y - 1 \\ add \: and \: subtract \: xy \: and \: x \\ = {x}^{2} - {y}^{2} - 2y - 1 + xy - xy + x - x\\ = {x}^{2} + xy + x - {y}^{2} - xy - y - y - x - 1\\x(x + y + 1) - y(y + x + 1) - y - x - 1 \\ = (x + y + 1)(x - y) - y - x - 1 \\ = (x + y + 1)(x - y) -(x + y + 1 ) \\ = (x + y + 1)(x - y -1)$