a)
\(\dfrac{x}{2}=\dfrac{3}{4}\)
\(\Rightarrow x.4=2.3\)
\(\Rightarrow x.4=6\)
\(\Rightarrow x=6:4\)
\(\Rightarrow x=\dfrac{3}{2}\)
b)
\(\dfrac{3}{x}=\dfrac{21}{17}\)
\(\Rightarrow x.21=3.17\)
\(\Rightarrow x.21=51\)
\(\Rightarrow x=51:21\)
\(\Rightarrow x=\dfrac{17}{7}\)
c)
\(\dfrac{x-2}{3}=\dfrac{4}{5}\)
\(\Rightarrow\left(x-2\right).5=3.4\)
\(\Rightarrow\left(x-2\right).5=12\)
\(\Rightarrow x-2=12:5\)
\(\Rightarrow x-2=\dfrac{12}{5}\)
\(\Rightarrow x=\dfrac{12}{5}+2\)
\(\Rightarrow x=\dfrac{22}{5}\)
d)
\(\dfrac{x-1}{x-5}=\dfrac{6}{7}\)
\(\Rightarrow\left(x-1\right).7=\left(x-5\right).6\)
\(\Rightarrow7x-7=6x-30\)
\(\Rightarrow7x-6x=7-30\)
\(\Rightarrow x=-23\)
a: x=3/4*2=3/2
b: =>x=3*17/-21=-51/21=-17/7
c: =>x-2=12/5
=>x=22/5
d: =>7x-7=6x-30
=>x=-23
