Question

Me ajudem pfvr Pfvvvr​

Answer 1

Ok , vamos lá !!

Letra A

$\sf \dfrac{1}{2} - ( \dfrac{1}{4} - \dfrac{1}{8} )$

$\sf = \dfrac{1}{2} - ( \dfrac{2\cdot 1 - 1\cdot 1}{8} )$

$\sf = \dfrac{1}{2} - ( \dfrac{2 - 1}{8} )$

$\sf = \dfrac{1}{2} - \dfrac{1}{8}$

$\sf = \dfrac{4\cdot 1 - 1\cdot 1}{8}$

$\sf = \dfrac{4 - 1}{8 }$

$\sf\red{ = \dfrac{3}{8} }$

Letra B

$\sf ( \dfrac{1}{2} - \dfrac{1}{4} ) - \dfrac{1}{8}$

$\sf = ( \dfrac{2\cdot 1 - 1\cdot 1}{4}) - \dfrac{1}{8}$

$\sf = ( \dfrac{2 - 1}{4}) - \dfrac{1}{8}$

$\sf = \dfrac{1}{4} - \dfrac{1}{8}$

$\sf = \dfrac{2\cdot 1 - 1\cdot 1}{8}$

$\sf = \dfrac{2- 1}{8}$

$\red{\sf = \dfrac{1}{8} }$

Bons estudos .