Question

If $x=\sqrt{\{{\left(105\right)}^2-{\left(100\right)}^2\}-1}$, then $x$ is equal to?

• A. $3.2$
• B. $1024$
• C. $102.4$
• D. $32$

Answer 1

The correct option is D $32$

$x=\sqrt{(205\times 5)-1}=\sqrt{1024}=32$.

(Use $a^2-b^2)=(a+b\left)\right(a-b)$