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a)\(\frac{-2}{3}.x+\frac{1}{5}=\frac{3}{10}\)
\(\frac{-2}{3}x=\frac{3}{10}-\frac{1}{5}=\frac{1}{10}\)
\(\frac{-2}{3}x=\frac{1}{10}\)
\(x=\frac{1}{10}\div\frac{-2}{3}=\frac{-3}{20}\)
b)\(\left(50\%.x+2\frac{1}{4}\right).\frac{-2}{3}=\frac{17}{6}\)
\(50\%.x+2\frac{1}{4}=\frac{17}{6}\div\frac{-2}{3}\)\(=\frac{-17}{4}\)
\(50\%.x+2\frac{1}{4}=\frac{-17}{4}\)
\(50\%.x=\frac{-17}{4}-2\frac{1}{4}=\frac{-17}{4}-\frac{9}{4}=\frac{-26}{4}=\frac{-13}{2}\)
\(50\%.x=\frac{-13}{2}\)
\(x=\frac{-13}{2}\div50\%=-13\)
\(\frac{-2}{3}\)\(\hept{\begin{cases}.\\.\\.\end{cases}ads}\)
\(\left(2\frac{4}{5}x-50\right)\div\frac{2}{3}=51\)
\(\frac{14}{5}x-50=51\times\frac{2}{3}\)
\(\frac{14}{5}x-50=34\)
\(\frac{14}{5}x=84\)
\(x=84\times\frac{5}{14}\)
\(x=30\)
\(a,\left(2\frac{4}{5}.x-50\right):\frac{2}{3}=51\)
\(\left(\frac{14}{5}.x-50\right):\frac{2}{3}=51\)
\(\frac{14}{5}.x-50=51\times\frac{2}{3}\)
\(\frac{14}{5}.x-50=34\)
\(\frac{14}{5}.x=34+50\)
\(\frac{14}{5}.x=84\)
\(x=84:\frac{14}{5}\)
\(x=\frac{405}{14}\)
50%=1/2
=>50%x+2/3x=1/2x+2/3x
<=>x(1/2+2/3)=x-5
<=>7/6x=x-5(Vô lí)
Vậy ko có x thỏa mãn
Sai r bạn e phải như thế này :
50%x + 2/3 x = x-5
1/2x + 2/3 x = x-5
x - x + x = 5 : (1/2+2/3)
x = -35
a) \(\frac{4}{3}x-1=\frac{x}{5}\)
=> \(\frac{4}{3}x-\frac{1}{5}x=1\)
=> \(\frac{17}{15}x=1\)
=> \(x=1:\frac{17}{15}=\frac{15}{17}\)
b) \(x+50\%=\frac{4\left(x+1\right)}{3}-\frac{1}{3}\)
=> \(x+\frac{1}{2}=\frac{4x+4-1}{3}\)
=> \(\frac{2x+1}{2}=\frac{4x+3}{3}\)
=> \(\left(2x+1\right).3=2.\left(4x+3\right)\)
=> \(6x+3=8x+6\)
=> \(6x-8x=6-3\)
=> \(-2x=3\)
=> \(x=3:\left(-2\right)=-\frac{3}{2}\)
\(a,\frac{4}{3}x-1=\frac{x}{5}\)
\(\Rightarrow\frac{4}{3}x=\frac{x}{5}+1\)
\(\Rightarrow\frac{4x}{3}=\frac{x+5}{5}\)
\(\Rightarrow20x=3x+15\)
\(\Rightarrow17x=15\)
\(\Rightarrow x=\frac{15}{17}\)
\(b,x+50\%=\frac{4\left(x+1\right)}{3}-\frac{1}{3}\)
\(\Rightarrow x+\frac{1}{2}=\frac{4x+4-1}{3}\)
\(\Rightarrow\frac{2x+1}{2}=\frac{4x+3}{3}\)
\(\Rightarrow3\left(2x+1\right)=\left(4x+3\right).2\)
\(\Rightarrow6x+3=8x+6\)
\(\Rightarrow2x=-3\)
\(\Rightarrow x=-\frac{3}{2}\)
\(c,-200\%.x+\frac{4}{3}=\frac{7}{4}\left(x+1\right)\)
\(\Rightarrow-2x+\frac{4}{3}=\frac{7}{4}x+\frac{7}{4}\)
\(\Rightarrow\frac{-6x+4}{3}=\frac{7x+7}{4}\)
\(\Rightarrow4\left(-6x+4\right)=\left(7x+7\right)3\)
\(\Rightarrow-24x+16=21x+21\)
\(\Rightarrow45x=-5\)
\(\Rightarrow x=-\frac{1}{7}\)
Bài 1:
\(\left(1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{49}-\frac{1}{50}\right)\):\(\left(\frac{1}{25}+\frac{1}{26}+....+\frac{1}{50}\right)\)
= \(\left[\left(1+\frac{1}{3}+\frac{1}{5}+...+\frac{1}{49}\right)-\left(\frac{1}{2}+\frac{1}{4}+...+\frac{1}{50}\right)\right]\):\(\left(\frac{1}{25}+\frac{1}{26}+....+\frac{1}{50}\right)\)
= \(\left[\left(1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{49}+\frac{1}{50}\right)-2\left(\frac{1}{2}+\frac{1}{4}+...+\frac{1}{50}\right)\right]\):\(\left(\frac{1}{25}+\frac{1}{26}+....+\frac{1}{50}\right)\)
=\(\left[\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{50}\right)-\left(1+\frac{1}{2}+\frac{1}{3}+...+\frac{1}{25}\right)\right]\):\(\left(\frac{1}{25}+\frac{1}{26}+....+\frac{1}{50}\right)\)
=\(\frac{1}{26}+\frac{1}{27}+....+\frac{1}{26}\):\(\left(\frac{1}{25}+\frac{1}{26}+....+\frac{1}{50}\right)\)
......????
bài này là violympic hay nâng cao