Question

simplify(a+b+c) (a+b-c)​

Answer 1

$(a+b+c) (a+b-c) \\ {a}^{2} + ab - ac + ab + {b}^{2} - bc + ac + bc - {c}^{2} \\ by \: adding \: we \: get \\ {a}^{2} + {b}^{2} - {c}^{2} + 2ab$

Hope this will be helpful.

Answer 2

Answer:

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

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

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

            + (c × a) + (c × b) - (c × c)

= a² + ab - ac + ba + b² - bc + ca +cb - c²

= a² + ab - ac + ab + b² - bc + ac +bc - c²

= a² + b² - c² + ab + ab - bc + bc - ac + ac

= a² + b² - c² + 2ab

Hope this helps you !!!!