Respuesta :
[tex] \sf \dashrightarrow \: - \frac{2}{5} - ( - \frac{3}{10} ) - ( - \frac{4}{7} )[/tex]
When there is a - in front of an expression in parentheses, change the sign of each term in the expression to +
[tex] \sf \dashrightarrow \: - \frac{2}{5} + \frac{3}{10} + \frac{4}{7} [/tex]
Calculate the LCM of denominators
[tex] \sf\frac{ - 28 + 21 + 40}{70} [/tex]
Calculate the difference
[tex] \bf \underline{ \underline \frac{33}{70} }[/tex]
[tex]\\ \rm\rightarrowtail \dfrac{-2}{5}-\left(-\dfrac{3}{10}\right)-\left(-\dfrac{4}{7}\right)[/tex]
- (-)(-)=(+)
[tex]\\ \rm\rightarrowtail \dfrac{-2}{5}+\dfrac{3}{10}+\dfrac{4}{7}[/tex]
[tex]\\ \rm\rightarrowtail \dfrac{-28+21+40}{70}[/tex]
[tex]\\ \rm\rightarrowtail \dfrac{-7+40}{70}[/tex]
[tex]\\ \rm\rightarrowtail \dfrac{33}{70}[/tex]
