Question

Without actual finding the square of the numbers, find the value of ${120}^2-{119}^2$.

• A. $239$
• B. $240$
• C. $238$
• D. $237$

Answer 1

Answer: (A)

$239$

Using the formula, $a^2-b^2=(a+b)(a-b)$
We get, ${120}^2-{119}^2=(120+119)(120-119)$
$=239\times 1$
$=239$.