Question

Sa se afle x nr rational

Answer 1

$\it a)\ \ \dfrac{x}{x+1}=\dfrac{6,3}{7,2} \Rightarrow \dfrac{x}{x+1-x}=\dfrac{6,3}{7,2-6,3} \Rightarrow x=\dfrac{6,3}{0,9} \Rightarrow x=0,7$

$\it b)\ \ \dfrac{2x-1}{x}=\dfrac{2,01}{\dfrac{101}{100}} \Rightarrow 2-\dfrac{1}{x}=\dfrac{201}{101} \Rightarrow 2-\dfrac{201}{101}=\dfrac{1}{x} \Rightarrow \\ \\ \\ \Rightarrow \dfrac{1}{101}=\dfrac{1}{x} \Rightarrow x=101$

$\it c)\ \dfrac{0,4}{3x}=\dfrac{5,6}{7} \Rightarrow \dfrac{0,4}{3x}=0,8 \Rightarrow 3x=\dfrac{0,4}{0,8} \Rightarrow 3x=\dfrac{1}{2}|_{:3} \Rightarrow x=\dfrac{1}{6}$