\(\frac{x}{12}-\frac{x}{15}=\frac{1}{6}\)
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\(\dfrac{3}{7}+\dfrac{1}{2}=\dfrac{-15}{12}x+\dfrac{6}{5}x\)
\(\Leftrightarrow\)\(\dfrac{-15.5+12.6}{60}x=\dfrac{3.2+1.7}{14}\)
\(\Leftrightarrow\)\(\dfrac{-3}{60}x=\dfrac{13}{14}\)
\(\Leftrightarrow\)\(\dfrac{-1}{20}x=\dfrac{13}{14}\)
\(\Leftrightarrow\)x=-\(\dfrac{13}{14}:\dfrac{1}{20}=-\dfrac{13.20}{14}=-\dfrac{130}{7}\)
3(12+x)=7(x-4)
\(\Leftrightarrow\)36+3x=7x-28
\(\Leftrightarrow\)7x-3x=36+28
\(\Leftrightarrow\)4x=64
\(\Leftrightarrow\)x=16
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\(\Leftrightarrow\frac{\frac{x-3+5}{5}}{4}=\frac{\frac{4x-3}{6}}{6}\Leftrightarrow\frac{x+2}{20}=\frac{4x-3}{36}\Leftrightarrow36x+72=80x-60\Leftrightarrow44x=132\Rightarrow x=2\)
\(\Leftrightarrow\frac{\frac{10x+x+2}{2}}{9}-\frac{\frac{x+3+75}{5}}{12}=x-2\)\(\Leftrightarrow\frac{11x+2}{18}-\frac{x+78}{60}=x-2\)\(\Leftrightarrow\left(\frac{11}{18}-\frac{1}{60}-1\right)x+\left(\frac{2}{18}-\frac{78}{60}+2\right)=0\).Giải típ nha, ko có Casio nên mk ko bấm
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\(\Rightarrow\frac{x}{15}=\frac{x}{12}-\frac{2}{12}\)
\(\Rightarrow\frac{x}{15}=\frac{x-2}{12}\)
\(\Leftrightarrow15.\left(x-2\right)=12x\)
\(\Rightarrow15x-30=12x\)
\(\Leftrightarrow15x-12x=30\)
\(\Leftrightarrow3x=30\)
\(\Rightarrow x=30:3\)
\(\Rightarrow x=10\)
\(\frac{x}{15}=\frac{x}{12}-\frac{1}{6}\)
\(\Leftrightarrow\frac{x}{15}=\frac{x-2}{12}\)
\(\Leftrightarrow12x=15\left(x-2\right)\)
\(\Leftrightarrow12x=15x-30\)
\(\Leftrightarrow3x-30=0\)
\(\Leftrightarrow3\left(x-10\right)=0\Leftrightarrow x-10=0\Leftrightarrow x=10\)\
Vậy x=10
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ĐKXĐ:\(x\ne1;2;3;4;5\)
\(\Leftrightarrow\frac{1}{x^2-x-2x+2}+\frac{1}{x^2-2x-3x+6}+\frac{1}{x^2-3x-4x+12}+\frac{1}{x^2-4x-5x+20}=\frac{1}{15}\)
\(\Leftrightarrow\frac{1}{\left(x-1\right)\left(x-2\right)}+\frac{1}{\left(x-2\right)\left(x-3\right)}+\frac{1}{\left(x-3\right)\left(x-4\right)}+\frac{1}{\left(x-4\right)\left(x-5\right)}=\frac{1}{15}\)
\(\Leftrightarrow\frac{1}{x-1}-\frac{1}{x-2}+\frac{1}{x-2}-\frac{1}{x-3}+\frac{1}{x-3}-\frac{1}{x-4}+\frac{1}{x-4}-\frac{1}{x-5}=\frac{1}{15}\)
\(\Leftrightarrow\frac{1}{x-1}-\frac{1}{x-5}=\frac{1}{15}\)
\(\Leftrightarrow\frac{15\left(x-5\right)-15\left(x-1\right)}{15\left(x-1\right)\left(x-5\right)}=\frac{\left(x-1\right)\left(x-5\right)}{15\left(x-1\right)\left(x-5\right)}\)
\(\Rightarrow15x-75-15x+15=x^2-6x+5\)
\(\Leftrightarrow x^2-6x+65=0\)
\(\Leftrightarrow\left(x^2-6x+9\right)+56=0\)
\(\Leftrightarrow\left(x-3\right)^2=-56\) (Vô lý)
Vì bình phương một số không thể bằng âm
Vây \(S=\varnothing\)
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\(-\frac{15}{12}x+\frac{3}{7}=\frac{6}{5}x-\frac{1}{2}\)
\(-\frac{15}{12}x-\frac{6}{5}x=-\frac{1}{2}-\frac{3}{7}\)
\(-\frac{49}{20}x=-\frac{13}{14}\)
\(x=\frac{130}{343}\)
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\(\frac{9}{15}x\frac{12}{1}x\frac{5}{6}\)=\(\frac{9x12x5}{15x1x6}\)=\(\frac{9x6x2x5}{5x3x1x6}\)= \(\frac{9x2}{3x1}\)=\(\frac{18}{3}\)= 6
Toán này đâu có phải toán lớp 1? Mà toán này là toán lớp 5.
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a)\(\frac{\frac{x-3}{5}+1}{4}=\frac{\frac{2x}{3}-\frac{1}{2}}{6}\)
\(\Rightarrow\frac{\frac{x-3+5}{5}}{4}=\frac{\frac{4x}{6}-\frac{3}{6}}{6}\)
\(\Rightarrow\frac{\frac{x+2}{5}}{4}=\frac{\frac{4x-3}{6}}{6}\)
\(\Rightarrow\frac{x+2}{5}:4=\frac{4x-3}{6}:6\)
\(\Rightarrow\frac{x+2}{5}.\frac{1}{4}=\frac{4x-3}{6}.\frac{1}{6}\)
\(\Rightarrow\frac{x+2}{20}=\frac{4x-3}{36}\)
\(\Rightarrow36.\left(x+2\right)=20.\left(4x-3\right)\)
\(\Rightarrow36x+72=80x-60\)
\(\Rightarrow72+60=80x-36x\)
\(\Rightarrow132=44x\)
\(\Rightarrow x=\frac{132}{44}=3\)
Vậy x=3
b)Bn làm tương tự phần a nha
Chúc bn học tốt
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Bạn tham khảo link này nha:https://olm.vn/hoi-dap/detail/246637974159.html
Chúc bn học tốt
\(\frac{x}{12}-\frac{x}{15}=\frac{1}{6}\)
\(\Leftrightarrow\frac{5x}{60}-\frac{4x}{60}=\frac{10}{60}\)
\(\Leftrightarrow5x-4x=10\)
\(\Leftrightarrow x=10\)
Ta có : \(\frac{x}{12}-\frac{x}{15}=\frac{1}{6}\)
=> \(\frac{15x}{12.15}-\frac{12x}{12.15}=\frac{1}{6}\)
=> \(\frac{15x-12x}{180}=\frac{1}{6}\)
=> \(\frac{3x}{180}=\frac{1}{6}\)
=> \(\frac{x}{60}=\frac{1}{6}\)
=> \(6x=60\)
=> \(x=60:6\)
=> \(x=10\)