Question

Simplify the following expression: $\sqrt{64}+\sqrt[3]{3-0.064}$

• A. 0
• B. 7.2
• C. 8.4
• D. 7.6

Answer 1

The correct option is D 7.6

$\text{Detailed step-by-step solution:}$
$\sqrt{64}=\sqrt{2\times 2\times 2\times 2\times 2\times 2}$
$=\sqrt{8\times 8}$
$=8$
$\sqrt[3]{3-0.064}=\sqrt[3]{3\frac{-64}{1000}}$
$=\sqrt[3]{3\frac{(-4)\times (-4)\times (-4)}{10\times 10\times 10}}$
$=\frac{\sqrt[3]{3(-4)\times (-4)\times (-4)}}{\sqrt[3]{310\times 10\times 10}}$
$=\frac{-4}{10}=-0.4$
So, $\sqrt{64}+\sqrt[3]{3-0.064}$
$=8+(-0.4)$
$=8-0.4$
$=7.6$

So, option B is the correct answer.