Question

Evaluate the following by using the identities:
${998}^2$

Answer 1

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

By using this identity, we have

${998}^2=(1000-2{)}^2$

$={1000}^2+2^2-2\times 1000\times 2$

$=1000000+4-4000$

$=996004$