Question

Urgenteeeeeee
Quanto é
2/4 = 3/x
5/2 = 20/x
2/3 = 5/x

Answer 1

Olá!!  :)

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Multiplicamos o meio pelos extremos:

1.  

$\sf \\\\ \Rightarrow \ \ \ \frac{2}{4} \ = \ \frac{3}{x} \\\\ \Rightarrow \ \ \ 2x \ = \ 12 \\\\ \Rightarrow \ \ \ x \ = \ \frac{12}{2} \\\\ \Rightarrow \ \ \boxed{ \sf \ x \ = \ 6 \ }$

2.  

$\sf \\\\ \Rightarrow \ \ \ \frac{5}{2} \ = \ \frac{20}{x} \\\\ \Rightarrow \ \ \ 5x \ = \ 40 \\\\ \Rightarrow \ \ \ x \ = \ \frac{40}{5} \\\\ \Rightarrow \ \ \boxed{ \sf \ x \ = \ 8 \ }$

3.

$\sf \\\\ \Rightarrow \ \ \ \frac{2}{3} \ = \ \frac{5}{x} \\\\ \Rightarrow \ \ \ 2x \ = \ 15 \\\\ \Rightarrow \ \ \ x \ = \ \frac{15}{2} \\\\ \Rightarrow \ \ \boxed{ \sf \ x \ = \ 7,5 \ }$

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Espero ter ajudado, bons estudos!!  :)