Question

1+2ab-a2-b2 factorisation

Answer 1

See the solution above

Answer 2

hiii,

1 + 2ab - a^2 - b^2
= - (a^2 - 2ab +b^2) +1
= - (a - b) ^2 +1
= (a - b)^2 - 1
= (a - b + 1)(a - b -1)

hope helps