\(\frac{1}{3}x:\frac{2}{3}=1\frac{3}{4}:\frac{2}{5}\)

\(\Rightarrow\frac{1}{3}x:\frac{2}{3}=\frac{35}{8}\)

\(\Rightarrow\frac{1}{3}x=\frac{35}{12}\)

\(\Rightarrow x=\frac{35}{4}\)

a) \(\left(\frac{1}{3}\cdot x\right):\frac{2}{3}=1\frac{3}{4}:\frac{2}{5}\)

\(=\left(\frac{1}{3}\cdot x\right):\frac{2}{3}=\frac{35}{8}\)

\(\Rightarrow\frac{1}{3}\cdot x=\frac{35}{8}\cdot\frac{2}{3}\)

\(\Rightarrow x=\frac{35}{12}:\frac{1}{3}=\frac{35}{4}\)

b) \(4,5:0,3=2,5:\left(0,1\cdot x\right)\)

\(=15=2,5:\left(0,1\cdot x\right)\)

\(\Rightarrow0,1\cdot x=2,25:15\)

\(\Rightarrow x=\frac{3}{20}:0,1=\frac{3}{2}=1,5\)

c) \(8:\left(\frac{1}{4}\cdot x\right)=2:0,02\)

\(8:\left(\frac{1}{4}\cdot x\right)=100\)

\(\Rightarrow\frac{1}{4}\cdot x=8:100\)

\(\Rightarrow x=\frac{2}{25}:\frac{1}{4}=\frac{8}{25}=0,32\)

d) \(3:2\frac{1}{4}=\frac{3}{4}:\left(6\cdot x\right)\)

\(=\frac{4}{3}=\frac{3}{4}:\left(6:x\right)\)

\(\Rightarrow6\cdot x=\frac{3}{4}:\frac{4}{3}\)

\(\Rightarrow x=\frac{9}{16}:6=\frac{3}{32}=0,09375\)

\(3,8:\left(2x\right)=\frac{1}{4}:2\frac{2}{3}\)

\(3,8:\left(2x\right)=\frac{3}{32}\)

\(\Rightarrow2x=3,8:\frac{3}{32}\)

\(\Rightarrow x=\frac{608}{15}:2=\frac{304}{15}\)

\(\left(a\right)\) tức là bài a hay là gt trog tỉ lệ thức v pn?

a) ĐKXĐ: x khác +2

\(\frac{x-2}{2+x}-\frac{3}{x-2}-\frac{2\left(x-11\right)}{x^2-4}\)

<=> \(\frac{x-2}{2+x}-\frac{3}{x-2}=\frac{2\left(x-11\right)}{\left(x-2\right)\left(x+2\right)}\)

<=> (x - 2)^2 - 3(2 + x) = 2(x - 11)

<=> x^2 - 4x + 4 - 6 - 3x = 2x - 22

<=> x^2 - 7x - 2 = 2x - 22

<=> x^2 - 7x - 2 - 2x + 22 = 0

<=> x^2 - 9x + 20 = 0

<=> (x - 4)(x - 5) = 0

<=> x - 4 = 0 hoặc x - 5 = 0

<=> x = 4 hoặc x = 5

làm nốt đi 

\(\left(x-3\right)^3-2\left(x-1\right)=x\left(x-2\right)^2-5x^2\)

\(\Leftrightarrow x^3-9x^2+27x-27-2x+2=x^3-4x^2+4x-5x^2\)

\(\Leftrightarrow27x-2x-4x-27+2=0\)

\(\Leftrightarrow21x=25\)

\(\Leftrightarrow x=\frac{25}{21}\)

Hết ý tưởng,phá tung ra,sai chỗ nào tự sửa nhé !

\(\frac{\left(x+1\right)^2}{3}+\frac{\left(x+2\right)\left(x-3\right)}{2}=\frac{\left(5x-1\right)\left(x-4\right)}{6}+\frac{28}{3}\)

\(\Leftrightarrow\frac{2\left(x+1\right)^2+3\left(x+2\right)\left(x-3\right)-\left(5x-1\right)\left(x-4\right)}{6}=\frac{28}{3}\)

\(\Leftrightarrow\frac{2x^2+4x+2+3x^2-3x-18-5x^2-21x+4}{6}=\frac{28}{3}\)

\(\Leftrightarrow\frac{\left(4x-3x-21x\right)+\left(2-18+4\right)}{6}=\frac{56}{6}\)

\(\Leftrightarrow-20x-12=56\)

\(\Leftrightarrow-20x=68\)

\(\Leftrightarrow x=-\frac{17}{5}\)

Tự check lại nhá

\(\frac{x+1}{94}+\frac{x+2}{93}+\frac{x+3}{92}=\frac{x+4}{91}+\frac{x+5}{90}+\frac{x+6}{89}\)

\(\Leftrightarrow\left(\frac{x+1}{94}+1\right)+\left(\frac{x+2}{93}+1\right)+\left(\frac{x+3}{92}+1\right)=\left(\frac{x+4}{91}+1\right)+\left(\frac{x+5}{90}+1\right)+\left(\frac{x+6}{89}+1\right)\)

\(\Leftrightarrow\frac{x+95}{94}+\frac{x+95}{93}+\frac{x+95}{92}=\frac{x+95}{91}+\frac{x+95}{90}+\frac{x+95}{89}\)

\(\Leftrightarrow\left(x+95\right)\left(\frac{1}{94}+\frac{1}{93}+\frac{1}{92}-\frac{1}{91}-\frac{1}{90}-\frac{1}{89}\right)=0\)

Ta dễ thấy \(\frac{1}{94}+\frac{1}{93}+\frac{1}{92}-\frac{1}{91}-\frac{1}{90}-\frac{1}{89}< 0\) nên

\(x+95=0\Leftrightarrow x=-95\)

\(8:\left(\frac{1}{4}\cdot x\right)=2:0.028:\frac{x}{4}=1008\cdot\frac{4}{x}=100\)

<=>\(\frac{8\cdot4}{x}=100\frac{32}{x}=100x=\frac{32}{100}=0.32\)

làm 1 bài mẫu nha

a) \(\left(\frac{1}{3}.x\right):\frac{2}{3}=\frac{25}{6}\)

\(\Rightarrow\frac{1}{3}x=\frac{25}{9}\)

\(\Rightarrow x=\frac{25}{9}:\frac{1}{3}\)

\(\Rightarrow x=\frac{25}{3}\)

các bài sau dễ lắm

a) \(\left(\frac{1}{3}x\right):\frac{2}{3}=1\frac{2}{3}:\frac{2}{5}\)

\(\Rightarrow\frac{1}{3}x:\frac{2}{3}=\frac{25}{6}\)

\(\Rightarrow\frac{1}{3}x=\frac{5}{3}\)

\(\Rightarrow x=\frac{5}{3}:\frac{1}{3}\)

\(\Rightarrow x=5\)

a) \(\left(\frac{1}{3}\cdot x\right):\frac{2}{3}=1\frac{2}{3}:\frac{2}{5}\)

\(\left(\frac{1}{3}\cdot x\right):\frac{2}{3}=\frac{25}{6}\)

\(\frac{1}{3}x=\frac{25}{6}\cdot\frac{2}{3}\)

\(\frac{1}{3}x=\frac{25}{9}\)

\(x=\frac{25}{9}:\frac{1}{3}\)

\(x=\frac{25}{3}\)

b) \(4,5:0,3=2,25:\left(0,1x\right)\)

\(15=2,25:\left(0,1x\right)\)

\(2,25:15=0,1x\)

\(0,15=0,1x\)

\(0,15:0,1=x\)

\(1,5=x\)

c) \(8:\left(\frac{1}{4}\cdot x\right)=2:0,02\)

\(8:\left(\frac{1}{4}\cdot x\right)=100\)

\(\frac{1}{4}\cdot x=8:100\)

\(\frac{1}{4}\cdot x=0,08\)

\(x=0,08:\frac{1}{4}\)

\(x=0,32\)

d) \(3:2\frac{1}{4}=\frac{3}{4}:\left(6\cdot x\right)\)

\(\frac{4}{3}=\frac{3}{4}:\left(6\cdot x\right)\)

\(\frac{3}{4}:\frac{4}{3}=6\cdot x\)

\(\frac{9}{16}=6\cdot x\)

\(\frac{9}{16}:6=x\)

\(\frac{3}{32}=x\)

e) \(3,8:\left(2\cdot x\right)=\frac{1}{4}:2\frac{2}{3}\)

\(3,8:\left(2\cdot x\right)=\frac{3}{32}\)

\(2\cdot x=3,8:\frac{3}{32}\)

\(2\cdot x=\frac{608}{15}\)

\(x=\frac{608}{15}:2\)

\(x=\frac{304}{15}\)

f) \(\left(0,25\cdot x\right):3=\frac{5}{6}:0,125\)

\(\left(0,25\cdot x\right):3=\frac{20}{3}\)

\(0,25\cdot x=\frac{20}{3}\cdot3\)

\(0,25\cdot x=20\)

\(x=20:0,25\)

\(x=80\)

g) \(1\frac{1}{3}:0,8=\frac{2}{3}:\left(0,1\cdot x\right)\)

\(\frac{5}{3}=\frac{2}{3}:\left(0,1\cdot x\right)\)

\(\frac{2}{3}:\frac{5}{3}=0,1\cdot x\)

\(\frac{2}{5}=0,1x\)

\(\frac{2}{5}:0,1=x\)

\(4=x\)

(Nhớ thử lại kết quả nhé)