Question

Write the following in the expanded form:

(i)$(a+2b+c{)}^2$

Answer 1

Given, $(a+2b+c{)}^2$
Using Identity,
$(a+b+c{)}^2=a^2+b^2+c^2+2ab+2bc+2ca$
$\therefore (a+2b+c{)}^2$
$=a^2+(2b{)}^2+c^2+2\times a\times 2b+2\times 2b\times c+2\times c\times a$
$=a^2+4b^2+c^2+4ab+4bc+2ac$

Hence, $(a+2b+c{)}^2=a^2+4b^2+c^2+4ab+4bc+2ac.$