Question

Write the following in the expanded form:
$${(a+2b+c)}^{2}$$

Answer 1

Formula,

$$(a+b+c)^2=a^2+b^2+c^2+2ab+2bc+2ca$$

Given,

$$(a+2b+c)^2=a^2+(2b)^2+c^2+2a(2b)+2(2b)c+2ca$$

$$=a^2+4b^2+c^2+4ab+4bc+2ac$$