Question

quanto e (-7/10).(+3/7).(-5/9)

Answer 1

Olá.

$\mathsf{\left(\dfrac{-7}{10}\right)\cdot\left(\dfrac{3}{7}\right)\cdot\left(\dfrac{-5}{9}\right)=}\\\\\\ \mathsf{\dfrac{(-7)\cdot3\cdot(-5)}{10\cdot7\cdot9}=}\\\\\\ \mathsf{\dfrac{(-21)\cdot(-5)}{70\cdot9}=}\\\\\\ \mathsf{\dfrac{105}{630}}$

Simplificamos por 105...
$\mathsf{\left(\dfrac{105}{630}\right)^{:105}=\boxed{\mathsf{\dfrac{1}{6}}}}$

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Bons estudos.