\(0,5:x=1,2:\left(-1,5\right)\)
\(\Leftrightarrow0,5:x=-0,8\)
\(\Leftrightarrow x=0,5:\left(-0,8\right)\)
\(\Rightarrow x=-0,625\)
\(0,4:x=x:0,9\)
\(2x=0,9.0,4\)
\(2x=0,36\)
\(\Rightarrow x=0,36:2=0,18\)
a) 0,5: x=-0,8
x=0,5:(-0,8)
x=-0,625
b) \(\frac{0,4}{x}=\frac{x}{0,9}\Leftrightarrow x.x=0,4.0,9=0,36\)
\(\Leftrightarrow x^2=0,36\)
\(\Leftrightarrow x=\pm0,6\)
c) \(\frac{2x+1}{3}=\frac{x-5}{5}\)
\(\Leftrightarrow5\left(2x+1\right)=3\left(x-5\right)\)
\(\Leftrightarrow5.2x+5.1=3.x-3.5\)
\(\Leftrightarrow10x+5=3x-15\)
\(\Leftrightarrow10x-3x=-15-5\)
\(\Leftrightarrow7x=-20\Leftrightarrow x=\frac{-20}{7}\)
\(a.0,5:x=1,2:\left(-1,5\right)\)
\(\Rightarrow x\left(1,2\right)=\left(-1,5\right)\left(0,5\right)\)
\(\Rightarrow x=\frac{-1,5\cdot0,5}{1,2}=\frac{-0,75}{1,2}=\frac{5}{8}\)
\(b.0,4:x=x:0,9\)
\(\Rightarrow x\cdot x=0,4\cdot0,9\)
\(\Rightarrow x^2=\frac{9}{25}\)
\(\Rightarrow\orbr{\begin{cases}x=\frac{3}{5}\\x=\frac{-3}{5}\end{cases}}\)
\(c.\left(2x+1\right):3=\left(x-5\right):5\)
\(\Rightarrow\left(2x+1\right)\cdot5=3\left(x-5\right)\)
\(\Rightarrow10x+5=3x-15\)
\(\Rightarrow10x-3x=-15-5\)
\(7x=-20\)
\(\Rightarrow x=\frac{-20}{7}\)
