Add the following: a(a+b),b(b+c),c(a+c) and a2+b2+c2 [2 MARKS]
Concept: 1 Mark Application: 1 Mark ⇒a(a+b)+b(b+c)+c(a+c)+a2+b2+c2 ⇒a2+ab+b2+bc+c2+ca+a2+b2+c2 ⇒2a2+2b2+2c2+ab+bc+ca