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\(11-\left(3x-1\right)=\frac{9}{2}-\left(5-3,5x\right)\)
\(=>11-3x+1=\frac{9}{2}-5+3,5x\)
\(=>-3x+12=3,5x-\frac{1}{2}\)
\(=>-3x-3,5x=-\frac{1}{2}-12\)
\(=>-6,5x=-12,5\)
\(=>x=\frac{-12,5}{-6,5}=\frac{25}{13}\)
Ủng hộ nha
\(11-\left(3x-1\right)=\frac{9}{2}-\left(5-3,5x\right)\)
\(11-3x+1=\frac{9}{2}-5+3,5x\)
\(12-3x=-\left(0,5\right)+3,5x\)
\(12,5-3x=3,5x\)
\(12,5=6,5x\)
\(x=12,5:6,5=\frac{25}{13}\)
\(\frac{x+2}{5}=\frac{3x-4}{-3}\)
\(\Rightarrow\left(x+2\right).\left(-3\right)=\left(3x-4\right).5\)
\(\Rightarrow-3x-6=15x-20\)
Từ đây chuyển vế đổi dấu là xong nhé!
x+2/5=3x-4/-3
<=> (x+2).3=(3x-4).-3 (nhân chéo 2 vế)
<=> 3x+6=-9x+12
<=>12x=6
<=>x=6/12=1/2
vậy x=1/2
học tốt
\(\frac{121212}{161616}-\left(\frac{151515}{323232}-x\right)=2\)
=> \(\frac{3}{4}-\left(\frac{15}{32}-x\right)=2\)
=> \(\frac{15}{32}-x=\frac{3}{4}-2\)
=> \(\frac{15}{32}-x=-\frac{5}{4}\)
=> \(x=\frac{15}{32}-\frac{-5}{4}=\frac{15}{32}+\frac{5}{4}=\frac{55}{32}\)
b) \(\frac{x}{2}+\frac{x}{6}+\frac{x}{12}+\frac{x}{20}+\frac{x}{30}+\frac{x}{42}+\frac{x}{56}+\frac{x}{72}+\frac{x}{90}=\frac{9}{5}\)
=> \(\frac{x}{1\cdot2}+\frac{x}{2\cdot3}+\frac{x}{3\cdot4}+\frac{x}{4\cdot5}+\frac{x}{5\cdot6}+\frac{x}{6\cdot7}+\frac{x}{7\cdot8}+\frac{x}{8\cdot9}+\frac{x}{9\cdot10}=\frac{9}{5}\)
=> \(\frac{x}{1}-\frac{x}{2}+\frac{x}{2}-\frac{x}{3}+...+\frac{x}{9}-\frac{x}{10}=\frac{9}{5}\)
=> \(\frac{x}{1}-\frac{x}{10}=\frac{9}{5}\)
=> \(\frac{10x-x}{10}=\frac{9}{5}\)
=> \(\frac{9x}{10}=\frac{9}{5}\)
=> \(\frac{9x}{10}=\frac{9\cdot2}{5\cdot2}=\frac{18}{10}\)
=> x = 2
\(\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{x\left(x+1\right)}=\frac{2}{5}\)
\(\Rightarrow\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{x}-\frac{1}{x+1}=\frac{2}{5}\)
\(\Rightarrow\frac{1}{2}-\frac{1}{x+1}=\frac{2}{5}\)
\(\Rightarrow\frac{1}{x+1}=\frac{1}{2}-\frac{2}{5}\)
\(\Rightarrow\frac{1}{x+1}=\frac{1}{10}\)
=> x+1=10
=>x=9
\(\frac{5}{6}x+\frac{1}{2}-\frac{1}{3}x=0,75x-\frac{7}{8}\)
\(\frac{5}{6}x-\frac{1}{3}x-0,75x=-\frac{7}{8}-\frac{1}{2}\)
\(\frac{5}{6}x-\frac{1}{3}x-\frac{3}{4}x=-\frac{11}{8}\)
\(\frac{1}{2}x-\frac{3}{4}x=-\frac{11}{8}\)
\(-\frac{1}{4}x=-\frac{11}{8}\)
\(x=-\frac{11}{8}:-\frac{1}{4}\)
\(x=\frac{11}{2}\)
đề là gì x \(\in\)z hay là gì
\(|x+9|.2=1\)
\(|x+9|=2\)
\(\Rightarrow\orbr{\begin{cases}x+9=2\\x+9=-2\end{cases}\Rightarrow\orbr{\begin{cases}x=-7\\x=-11\end{cases}}}\)