Question

4 va rog repede dau puncte
Termenul necunoscut x din proportia 1,(6)/1,25-0,2(7)=4/x​

Answer 1

Ai rezolvarea, rasp D

Answer 2

Răspuns:

D

Explicație pas cu pas:

$1,(6) = \dfrac{16-1}{9} = \dfrac{15}{9} = \dfrac{5}{3}$

$0,2(7) = \dfrac{27-2}{90} = \dfrac{25}{90} = \dfrac{5}{18}$

$1,25 = \dfrac{125}{100} = \dfrac{5}{4}$

$\dfrac{\dfrac{5}{3}}{\dfrac{5}{4}-\dfrac{5}{18}}=\dfrac{4}{x} \iff \dfrac{5x}{3} = 4 \cdot \bigg(\dfrac{5}{4}-\dfrac{5}{18}\bigg)$

$\dfrac{5x}{3} = \ ^{9)} 5-\dfrac{10}{9} \iff \dfrac{5x}{3} = \dfrac{45-10}{9}$

$\dfrac{5x}{3} = \dfrac{35}{9} \iff x = \dfrac{3 \cdot 35}{5 \cdot 9}$

$\implies \bf x = \dfrac{7}{3}$