Question

Simplify and Evaluate

Answer 1

$\dfrac{2^{-1} + 5^{-1}}{10^{-1} - 5^{-2}} =$

$= \dfrac{\frac{1}{2} + \frac{1}{5}}{\frac{1}{10} - \frac{1}{5^2}}$

$=\dfrac{\frac{1}{2} + \frac{1}{5}}{\frac{1}{10} - \frac{1}{25}}$

$=\dfrac{\frac{5}{10} + \frac{2}{10}}{\frac{5}{50} - \frac{2}{50}}$

$=\dfrac{\frac{7}{10}}{\frac{3}{50}}$

$= \frac{7}{10} \times \frac{50}{3}$

$= \frac{7}{1} \times \frac{5}{3}$

$= \frac{35}{3}$