Question

Factorise: a2 + b2 – 2(ab – ac + bc).​

Answer 1

Expand the bracketed terms, use identity, then factorise the resulting expression.

Answer 2

(a2+ b2 - 2ab) - 2 (-ac + bc)

(a-b)square -2 (-c) ( a-b) = (a-b) [(a-b) + 2c]

(a-b) (a-b+2c)