a) Ta có: \(\frac{x}{9}=\frac{-12}{27}\)

=> \(27.x=-12.9\)

=> \(27x=-108\)

=> \(x=108:27\)

=>\(x=4\)

a/ \(\frac{3}{4}.x=12\Rightarrow x=16\)

b/ \(\frac{12.3}{4}=9\)

sao toàn mấy câu dễ thế

\(\frac{x}{12}=\frac{4}{3x-3}+\frac{1}{12}\)

\(\frac{x}{12}-\frac{1}{12}=\frac{4}{3\left(x-1\right)}\)

\(\frac{x-1}{12}=\frac{4}{3\left(x-1\right)}\)

=> ( x - 1 ) . 3 ( x - 1 ) = 48

=> ( x - 1 )² . 3 = 48

=> ( x - 1 )² = 16

Phần sau dễ bạn tự làm nốt nha

cảm ơn bạn nha

\(\frac{4}{3x-3}=\frac{4}{3\left(x-1\right)}\)

\(\Rightarrow\frac{x}{12}=\frac{4}{3\left(x-1\right)}+\frac{1}{12}=\frac{16}{12\left(x-1\right)}+\frac{x-1}{12\left(x-1\right)}=\frac{16+x-1}{12\left(x-1\right)}\)

\(\Rightarrow\)12x(x-1) = 12(16 + x - 1)

          12x²  - 12x = 12.16 + 12x - 12

=> 12x² = 192 + 24x - 12

=> 12x² - 24x = 180

=>12x(x - 2) = 180

 x(x - 2) = 65

Bạn làm nốt nhé, mình đang bận

\(\frac{x}{2}+\frac{x}{3}+\frac{x}{6}=\frac{13}{12}\)

<=>\(\frac{3x}{6}+\frac{2x}{6}+\frac{x}{6}=\frac{13}{12}\)

<=>\(\frac{3x+2x+x}{6}=\frac{13}{12}\)

<=>\(\frac{6x}{6}=\frac{13}{12}\)

<=>x =\(\frac{13}{12}\).

Chúc bạn học tốt!

\(\frac{x}{2}+\frac{x}{3}+\frac{x}{6}=\frac{13}{12}\)

\(\frac{6x}{12}+\frac{4x}{12}+\frac{2x}{12}=\frac{13}{12}\)

\(\frac{12x}{12}=\frac{13}{12}\)

\(\Rightarrow x=\frac{13}{12}\)

\(\frac{x}{2}+\frac{x}{3}+\frac{x}{6}=\frac{13}{12}\)

\(\Leftrightarrow\frac{6x+4x+2x}{12}=\frac{13}{12}\)

\(\Leftrightarrow6x+4x+2x=13\Leftrightarrow12x=13\Leftrightarrow x=\frac{13}{12}\)

Có lẽ bạn viết đề sai.

Câu hỏi của Vũ Mai Linh - Toán lớp 7 - Học toán với OnlineMath

mik viết đề đúng mà sai chỗ nào vayh

\(\frac{-11}{6}.x+\frac{3}{2}.x-1\frac{2}{3}=\frac{5}{12}\)

=> \(\left(-\frac{11}{6}+\frac{3}{2}\right).x=\frac{5}{12}+\frac{5}{3}\)

=> \(-\frac{1}{3}.x=\frac{25}{12}\)

=> \(x=\frac{25}{12}:\left(-\frac{1}{3}\right)\)

=> \(x=-\frac{25}{4}\)

\(\frac{-11}{6}x+\frac{3}{2}x-1\frac{2}{3}=\frac{5}{12}\)

\(\Rightarrow\left(-\frac{11}{6}+\frac{3}{2}\right)x-\frac{5}{3}=\frac{5}{12}\)

\(\Rightarrow\left(-\frac{11}{6}+\frac{9}{6}\right)x-\frac{5}{3}=\frac{5}{12}\)

\(\Rightarrow-\frac{1}{3}x-\frac{5}{3}=\frac{5}{12}\)

\(\Rightarrow-\frac{1}{3}x=\frac{5}{12}+\frac{5}{3}\)

\(\Rightarrow-\frac{1}{3}x=\frac{5}{12}+\frac{20}{12}\)

\(\Rightarrow-\frac{1}{3}x=\frac{25}{12}\)

\(\Rightarrow x=\frac{25}{12}:\left(-\frac{1}{3}\right)\)

\(\Rightarrow x=\frac{25}{12}.\left(-3\right)\)

\(\Rightarrow x=\frac{-75}{12}\)

\(\Rightarrow x=\frac{-25}{4}\)

\(\frac{x}{2}+\frac{x}{3}+\frac{x}{4}=-\frac{13}{12}\)

\(\Rightarrow x\left(\frac{1}{2}+\frac{1}{3}+\frac{1}{4}\right)=\frac{-13}{12}\)

\(\Rightarrow x.\frac{13}{12}=\frac{-13}{12}\)

\(\Rightarrow x=-1\)

\(\frac{x}{2}+\frac{x}{3}+\frac{x}{4}=-\frac{13}{12}\)

\(\Rightarrow\frac{6x}{12}+\frac{4x}{12}+\frac{3x}{12}=-\frac{13}{12}\)

\(\Leftrightarrow6x+4x+3x=-13\)

\(\Leftrightarrow13x=-13\)

\(\Leftrightarrow x=-1\)

\(\frac{x}{2}+\frac{x}{3}+\frac{x}{4}=\frac{-13}{12}\)

\(\Leftrightarrow\frac{6x}{12}+\frac{4x}{12}+\frac{3x}{12}=\frac{-13}{12}\)

\(\Leftrightarrow\frac{6x+4x+3x}{12}=\frac{-13}{12}\)

\(\Leftrightarrow\frac{x\times\left(6+4+3\right)}{12}=\frac{-13}{12}\)

\(\Leftrightarrow\frac{x\times13}{12}=\frac{-13}{12}\)

\(\Leftrightarrow x\times13=-13\)

                   \(x=-13:13\)

             \(\Rightarrow x=-1\)

\(-\frac{5}{9}-\left(-\frac{5}{12}\right)\)

\(=-\frac{5}{9}+\frac{5}{12}\)

\(=-\frac{5}{36}\)

*Tìm x

\(-\frac{5}{6}-x=\frac{7}{12}+\left(-\frac{1}{3}\right)\)

\(\Rightarrow-\frac{5}{6}-x=\frac{1}{4}\)

\(\Rightarrow x=-\frac{5}{6}-\frac{1}{4}\)

\(\Rightarrow x=-\frac{13}{12}\)

\(\frac{-5}{9}-\frac{-5}{12}\)

= \(\frac{-20}{36}-\frac{-15}{36}\)

= \(\frac{-5}{36}\)

Tìm x:

\(\frac{-5}{6}-x=\frac{7}{12}+\frac{-1}{3}\)

\(\frac{-5}{6}-x=\frac{7}{12}+\frac{-4}{12}\)

\(\frac{-5}{6}-x=\frac{1}{4}\)

\(x=\frac{-5}{6}-\frac{1}{4}\)

\(x=\frac{-10}{12}-\frac{3}{12}\)

\(x=\frac{-13}{12}\)