Question

Find the squares of $510$ using the identity
$(a+b{)}^2=a^2+2ab+b^2$

Answer 1

${510}^2={(500+10)}^2$
It is the form of ${(a+b)}^2$, where $a=500,b=10$
Applying the formula ${(a+b)}^2=a^2+b^2+2ab$
${510}^2={(500+10)}^2={500}^2+{10}^2+2\times 500\times 10=250000+100+10000=260100$