Question

expand the question​

Answer 1

${(a + b + c)}^{2} = {a}^{2} + {b}^{2} + {c}^{2} + 2ab + 2bc + 2ca \\ \\ now \\ \\ {(a + ( - 2b) + ( - 3c))}^{2} = {a}^{2} + 4 {b}^{2} + 9 {c}^{2} - 4ab + 12bc - 6ac \\ \\ \\ \\ \: \: \: \: \: \: \: \: \: \bold{ \large{hope \: it \: helps}}$