Question

E URGENT!!!! DAU COROANA!!
aflati nr x din proportia de mai sus. cu explicatie va roog​

Answer 1

Pentru mai multa claritate: notam a=1/x

Astfel avem:

a/5=3/4

Facem produsele in diagonala:

a*4=5*3=15

4a=15, deci a=15/4

Dar a=1/x, deci x=1/a=4/15

x=4/15

Answer 2

$\it \dfrac{\dfrac{1}{x}}{5}=\dfrac{3}{4} \Rightarrow \dfrac{1}{x}:5=\dfrac{3}{4} \Rightarrow \dfrac{1}{x}:\dfrac{5}{1}=\dfrac{3}{4}\Rightarrow \dfrac{1}{x}\cdot\dfrac{1}{5}=\dfrac{3}{4}\Rightarrow\dfrac{1}{5x}=\dfrac{3}{4}\Rightarrow \dfrac{5x}{1}=\dfrac{4}{3}\Rightarrow\\ \\ \\ \Rightarrow 5x=\dfrac{4}{3}\Rightarrow x=\dfrac{4}{3}:5 \Rightarrow x=\dfrac{4}{3}:\dfrac{5}{1} \Rightarrow x=\dfrac{4}{3}\cdot\dfrac{1}{5}\Rightarrow x=\dfrac{4}{15}$