Question

Add : a2+ 3ab – bc , b2+ 3bc – ca and c2+ 3ca –ab

Answer 1

Answer:

a2+2ab+2bc+b2+2ca+c2

Answer 2

Answer:

${a}^{2} + 3ab - bc + {b}^{2} + 3bc - ca + {c}^{2} + 3ca - ab \\ = {a}^{2} + 3ab - ab - bc + 3bc + {b}^{2} - ca + 3ca \\ = {a}^{2} + 2ab - 2bc + {b}^{2} + 2ca \\ = {a}^{2} + {b}^{2} + 2ab - 2bc + 2ca$

Hope it helps you