Question

Using identities, evaluate: $9.5\times 10.05$

Answer 1

We have, $9.5\times 10.05$
$=(10-0.5)\times (10+0.5)$
$=({10}^2-{0.5}^2)$ [Using tthe identity, $(a-b)(a+b)=(a^2-b^2)$]
$=(100-0.25)$
$=99.75$