Question

What is the value of the numerical expression below? -\frac{2}{5}\ \div\left(\frac{8}{7}\times\frac{-7}{8}\right)\ \div-1− 5 2 ​ ÷( 7 8 ​ × 8 −7 ​ ) ÷−1 Show your work. A. -1 B. -\frac{2}{5}− 5 2 ​ C. \frac{2}{5} 5 2 ​ D. 1

Answer 1

Given:

The expression is

$-\dfrac{2}{5}\ \div\left(\dfrac{8}{7}\times\dfrac{-7}{8}\right)\ \div-1$

To find:

The numerical value of the given expression.

Solution:

We have,

$-\dfrac{2}{5}\div\left(\dfrac{8}{7}\times\dfrac{-7}{8}\right)\ \div-1$

On simplification, we get

$=-\dfrac{2}{5}\div\left(-1\right)\ \div-1$

$=-\dfrac{2}{5}\div \dfrac{-1}{-1}$

$=-\dfrac{2}{5}\div 1$

$=-\dfrac{2}{5}$             $[\because a\div 1=a]$

Therefore, the numerical value of the given expression is $-\dfrac{2}{5}$ and the correct option is B.