Question

The value of $(509{)}^2$ is _______.

• A. $250981$
• B. $529081$
• C. $259081$
• D. $295081$

Answer 1

The correct option is C $259081$

$509=500+9$

Using the identity:
$(a+b{)}^2$= $(a{)}^2+2\times a\times b+(b{)}^2$,
$(500+9{)}^2=(500{)}^2+2\times 500\times 9+(9{)}^2$
$=250000+9000+81$
$=259081$