Question

a^2 + b^2 - 2(ab - ac + bc ) factorise

Answer 1

(a^2+b^2-2ab)+2ac-2bc
=(a-b)^2 +2c(a-b)
=(a-b)(a-b+2c)

Answer 2

a^2 + b^2 - 2(ab - ac +bc)

= a^2 + b^2 - 2ab + 2ac - 2bc

= (a- b)^2 + 2ac - 2bc [ we know that a^2 + b^2 - 2ab
= (a-b)^2]

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

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

Hope it helps..