Question

Plz answer this question. It's very urgent.!​!

Answer 1

Answer:

Step-by-step explanation:

(a+b+c)^3-a^3-b^3-c^3=3(a+b)(b+c)(c+a)

solve L.H.S by dividing  L.H.S in two parts

[(a+b+c)^3-a^3]-[b^3+c^3]

[(a+b+c-a){(a+b+c)^2+(a^2)+a(a+b+c)}]-[(b+c)(b^2+c^2-bc)]

[(b+c){(a^2+b^2+c^2+2(ab+bc+ca)+a^2+a^2+ab+ac)}]-[(b+c)(b^2+c^2-bc)]

[(b+c){a^2+b^2+c^2+2(ab+bc+ca)+a^2+a^2+ab+ca}]-[(b+c)(b^2+c^2-bc)]

(b+c){a^2+b^2+c^2+2(ab+bc+ca)+a^2+a^2+ab+ac-b^2-c^2+bc}

(b+c){3a^2+3ab+3bc+3ac}

(b+c){3(a^2+ab+bc+ca)}

3(b+c){a(a+b)c(b+a)}

3(b+c){(a+c)(a+b)}

3(b+c)(a+c)(a+b)=R.H.S