Question

sendo a =(-2/3)2 ÷(-2/3)3 e b =(-1/4) x 8/3 calcule: A)a B)b C) A x B D)A-B

Answer 1

Explicação passo-a-passo:

a) $\sf A=\left(-\dfrac{2}{3}\right)^2\div\left(-\dfrac{2}{3}\right)^3$

$\sf A=\left(-\dfrac{2}{3}\right)^{2-3}$

$\sf A=\left(-\dfrac{2}{3}\right)^{-1}$

$\sf A=\dfrac{-3}{2}$

b) $\sf B=\left(-\dfrac{1}{4}\right)\times\dfrac{8}{3}$

$\sf B=\dfrac{-8}{12}$

$\sf B=\dfrac{-2}{3}$

c) $\sf A\times B=\left(-\dfrac{3}{2}\right)\times\left(-\dfrac{2}{3}\right)$

$\sf A\times B=\dfrac{6}{6}$

$\sf A\times B=1$

d) $\sf A-B=\left(-\dfrac{3}{2}\right)-\left(-\dfrac{2}{3}\right)$

$\sf A-B=\dfrac{-3}{2}+\dfrac{2}{3}$

$\sf A-B=\dfrac{(-3)\cdot3+2\cdot2}{6}$

$\sf A-B=\dfrac{-9+4}{6}$

$\sf A-B=\dfrac{-5}{6}$

Answer 2

Explicação passo-a-passo:

A)

$( \frac{ - 2}{3})2 \div ( \frac{ - 2}{3} )3$

$(\frac{ - 2 \times 2}{3} ) \div ( \frac{ - 2 \times 3}{3} )$

$( \frac{ - 4}{3 }) \div (\frac{ - 6}{3} )$

Agora para dividir multiplicamos pelo inverso da segunda fração.

$( \frac{ - 4}{3} ) \times ( \frac{3}{ - 6} )$

$\frac{2}{3}$

B)

$( \frac{ - 1}{4}) \times \frac{8}{3} \\ \frac{ - 2}{3}$

C)

A-B

$( \frac{2}{ 3}) - ( \frac{ - 2}{3} )$

$\frac{2 + 2}{3}$

$\frac{4}{3}$