Question

$\text{Find the value of}{23}^2\text{by using identities.}$

Answer 1

$(a+b{)}^2=a^2+2ab+b^2$

${23}^2=(20+3{)}^2$

$\text{Now we will use the algebraic identity}(a+b{)}^2=a^2+2ab+b^2$

$(20+3{)}^2={20}^2+2\times 20\times 3+3^2$

$=400+120+9$

$=529$