Question

Evaluate

\[-\dfrac{2}{5}-x+\left(-\dfrac{9}{10}\right)\] where

\[x = \dfrac{4}{5}\].

Answer 1

`-(21)/(10)`

Explanation:

Evaluate:

`-(2)/(5)-x+\left(-(9)/(10)\right)`

for

`x = (4)/(5)`

`-(2)/(5)-x +\left(-(9)/(10)\right) =`

`= -(2)/(5)-(4)/(5) +\left(-(9)/(10)\right)`

`= -(4)/(10)-(8)/(10) +\left(-(9)/(10)\right)`

`= -(12)/(10) +\left(-(9)/(10)\right)`

`= -(21)/(10)`