Question

Expand ${(a+5)}^2$ using appropriate identity

Answer 1

Using, the identity $(x+y{)}^2=x^2+y^2+2xy$.

Given, $(a+5{)}^2$ we apply the above identity as follows:

$(a+5{)}^2=a^2+5^2+(2\times a\times 5)=a^2+25+10a$

Hence, $(a+5{)}^2=a^2+10a+25$.