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Bài 2:
a: =>x/4=1/8
hay x=1/2
b: \(\Leftrightarrow\dfrac{x}{-5}=\dfrac{11}{6}\)
hay x=-55/6
c: \(\Leftrightarrow\dfrac{-3.5}{x}=\dfrac{4.25}{8}\)
hay x=-112/17
a)\(\frac{x-1}{x+2}=\frac{x-2}{x+3}\Rightarrow\left(x-1\right)\left(x+3\right)=\left(x+2\right)\left(x-2\right)\)
\(\Rightarrow x^2+2x-3=x^2-4\)
\(\Rightarrow2x=-1\)
\(\Rightarrow x=-\frac{1}{2}\)
b)\(\frac{37-x}{x+13}=\frac{3}{7}\)\(\Rightarrow7\left(37-x\right)=3\left(x+13\right)\)
\(\Rightarrow259-7x=3x+39\)
\(\Rightarrow10x=220\)
\(\Rightarrow x=22\)
\(a,\frac{3x+2}{5x+7}=\frac{3x-1}{5x-1}=\frac{\left(3x+2\right)-\left(3x-1\right)}{\left(5x+7\right)-\left(5x-1\right)}=\frac{3}{8};\frac{3x+2}{5x+7}=\frac{3}{8}\Leftrightarrow24x+16=15x+21\Leftrightarrow9x=5\Leftrightarrow x=\frac{5}{9}\) \(b,\frac{37-x}{x+13}=\frac{3}{7}\Leftrightarrow37.7-7x=3x+39\Leftrightarrow259-7x=3x+39\Leftrightarrow220-7x=3x\Leftrightarrow10x=220\Leftrightarrow x=22\) \(c,\frac{x+1}{2x+1}=\frac{0,5x+2}{x+3}=\frac{x+4}{2x+6}=\frac{\left(x+4\right)-\left(x+1\right)}{2x+6-\left(2x+1\right)}=\frac{3}{5};\frac{x+1}{2x+1}=\frac{3}{5}\Leftrightarrow5x+5=6x+3\Leftrightarrow x=2\) \(d,\frac{x-2}{x+2}=\frac{x+3}{x-4}=\frac{\left(x+3\right)-\left(x-2\right)}{\left(x-4\right)-\left(x+2\right)}=\frac{5}{-6};\frac{x-2}{x+2}=\frac{5}{-6}\Leftrightarrow6\left(2-x\right)=5x+10\Leftrightarrow2-6x=5x\Leftrightarrow x=\frac{2}{11}\) \(f,\frac{3x-5}{x}=\frac{9x}{3x+2}=\frac{9x-15}{3x}=\frac{9x-\left(9x-15\right)}{\left(3x+2\right)-3x}=\frac{15}{2};\frac{9x}{3x+2}=\frac{15}{2}\Leftrightarrow18x=45x+30\Leftrightarrow27x+30=0\Leftrightarrow x=\frac{-10}{9}\) \(e,\frac{x+2}{6}=\frac{5x-1}{5}\Leftrightarrow5\left(x+2\right)=6\left(5x-1\right)\Leftrightarrow5x+10=30x-6\Leftrightarrow10=25x-6\Leftrightarrow25x=16\Leftrightarrow x=\frac{16}{25}\)
a) (3x-2):\(1\frac{2}{5}\)=\(2\frac{3}{7}\)
(3x-2):\(\frac{7}{5}\)=\(\frac{17}{7}\)
3x-2 =\(\frac{17}{7}.\frac{7}{5}\)
3x-2 =\(\frac{17}{5}\)
3x =\(\frac{17}{5}+2\)
3x =\(\frac{27}{5}\)
x =\(\frac{27}{5}:3\)
x =\(\frac{27}{5}.\frac{1}{3}\)
x =\(\frac{9}{5}\)
b) x:0,16=9:x
x.x =9.0,16
x2 =\(\frac{36}{25}\)
x2 =\(\left(\frac{6}{5}\right)^2\)
⇒x =\(\frac{6}{5}\)
a) Ta có: \(\left(3x-2\right):1\frac{2}{5}=2\frac{3}{7}:2\frac{3}{5}\)
\(\Leftrightarrow\left(3x-2\right):\frac{7}{5}=\frac{17}{7}:\frac{13}{5}\)
\(\Leftrightarrow\left(3x-2\right)\cdot\frac{5}{7}=\frac{17}{7}\cdot\frac{5}{13}=\frac{85}{91}\)
\(\Leftrightarrow3x-2=\frac{85}{91}:\frac{5}{7}=\frac{85}{91}\cdot\frac{7}{5}=\frac{17}{13}\)
\(\Leftrightarrow3x=\frac{17}{13}+2=\frac{43}{13}\)
\(\Leftrightarrow x=\frac{43}{13}:3=\frac{43}{13}\cdot\frac{1}{3}\)
hay \(x=\frac{43}{39}\)
Vậy: \(x=\frac{43}{39}\)
b) ĐKXĐ: x≠0
Ta có: \(\frac{x}{0.16}=\frac{9}{x}\)
\(\Leftrightarrow x\cdot x=9\cdot0.16\)
\(\Leftrightarrow x^2=1.44\)
hay \(x\in\left\{1.2;-1.2\right\}\)(nhận)
Vậy: \(x\in\left\{1.2;-1.2\right\}\)
a) \(\frac{3x-2}{1\frac{2}{5}}=\frac{2\frac{3}{7}}{2\frac{3}{5}}\Rightarrow3x-2=1.\frac{2}{5}.\frac{2\frac{3}{7}}{2\frac{3}{5}}=\frac{7}{5}.\frac{17}{7}.\frac{5}{13}\)
\(3x-2=\frac{17}{13}\Rightarrow3x=2+\frac{17}{13}=\frac{43}{13}\Rightarrow x=\frac{43}{39}.\)
b) \(\frac{x}{0,16}=\frac{9}{x}\Rightarrow x^2=9.0,16=1,44\Rightarrow x=\pm1,2\)