Question

expand (​2a+3b+4c)^2

Answer 1

Using the formula, (a+b+c)^2 = a^2+b^2+c^2+2ab+2bc+2ca
(2a+3b+4c)^2 = (2a)^2+(3b)^2+(4c)^2+2(2a*3b)+2(3b*4c)+2(4c*2a)
(2a+3b+4c)^2 = 4a^2+9b^2+16c^2+12ab+24bc+16ca