a) \(x-\frac{5}{7}=\frac{1}{9}\Rightarrow x=\frac{1}{9}+\frac{5}{7}\Rightarrow x=\frac{52}{63}\)

b) \(\frac{-3}{7}-x=\frac{4}{5}+\frac{-2}{3}\Rightarrow\frac{-3}{7}-x=\frac{2}{15}\Rightarrow x=\frac{-3}{7}-\frac{2}{15}\Rightarrow x=\frac{-59}{105}\)

c) \(x-\frac{1}{5}=\frac{2}{7}.\frac{-11}{5}\Rightarrow x-\frac{1}{5}=\frac{-22}{35}\Rightarrow x=\frac{-22}{35}+\frac{1}{5}\Rightarrow x=\frac{-3}{7}\)

d) \(\frac{x}{182}=\frac{-6}{14}.\frac{35}{91}\Rightarrow\frac{x}{182}=\frac{-15}{91}\Rightarrow x=\frac{\left(-15\right).182}{91}\Rightarrow x=-30\)

a) \(-\frac{2x}{5}=\frac{-6}{3}\)

\(\Rightarrow-2x.3=-6.5\)

\(\Rightarrow-2x=\frac{-6.5}{3}\)

\(\Rightarrow-2x=-10\)

\(\Rightarrow x=\frac{-10}{-2}\)

\(\Rightarrow x=5\)

b) \(\frac{x-2}{18}=\frac{-1}{6}\)

\(\Rightarrow\left(x-2\right).6=-1.18\)

\(\Rightarrow x-2=\frac{-1.18}{6}\)

\(\Rightarrow x-2=-3\)

\(\Rightarrow x=-3+2\)

\(\Rightarrow x=-1\)

c) \(\frac{x}{14}=\frac{6}{y}=\frac{-15}{35}\)

\(\Rightarrow\left[\begin{matrix}\frac{x}{14}=\frac{-15}{35}\\\frac{6}{y}=\frac{-15}{35}\end{matrix}\right.\Rightarrow\left[\begin{matrix}x.35=-15.14\\6.35=-15.y\end{matrix}\right.\)

\(\Rightarrow\left[\begin{matrix}x=\frac{-15.14}{35}\\y=\frac{6.35}{-15}\end{matrix}\right.\Rightarrow\left[\begin{matrix}x=-6\\y=-14\end{matrix}\right.\)

Vậy \(x=-6;y=-14\)

a) \(\frac{-2x}{5}=-\frac{6}{3}\)

\(\Leftrightarrow-6x=-30\)

\(\Leftrightarrow x=5\)

b) \(\frac{x-2}{18}=-\frac{1}{6}\)

\(\Leftrightarrow-6\left(x-2\right)=-18\)

\(\Leftrightarrow x-2=3\)

\(\Leftrightarrow x=5\)

c) \(\frac{x}{14}=\frac{6}{y}=-\frac{15}{35}\)

\(\Leftrightarrow\frac{x}{14}=\frac{6}{y}=-\frac{3}{7}\)

\(\Leftrightarrow\left\{\begin{matrix}x=-6\\y=-14\end{matrix}\right.\)

a, \(\frac{3}{7}=-\frac{x}{21}\Leftrightarrow63=-7x\Leftrightarrow x=-9\)

b, \(\frac{x-1}{6}=\frac{2}{3}\Leftrightarrow\frac{x-1}{6}=\frac{4}{6}\Leftrightarrow x-1=4\Leftrightarrow x=5\)

c, \(\frac{-15}{2x+3}=\frac{-5}{8}\Leftrightarrow-120=-10x-15\Leftrightarrow-10x=-105\Leftrightarrow x=10,5\)( chưa xem lại ko chắc , thử lại giúp mk nha ) 

a) \(\frac{3}{7}=\frac{-x}{21}\)

\(\Rightarrow-7x=21.3\)

        \(-7x=63\)

               \(x=63:\left(-7\right)\)

               \(x=-9\)

Vậy x=-9

b) \(\frac{x-1}{6}=\frac{2}{3}\)

\(\Rightarrow\left(x-1\right).3=6.2\)

             \(3x-3=12\)

                       \(3x=12+3\)

                       \(3x=15\)

                          \(x=15:3\) 

                          \(x=5\)

Vậy x=5

a, \(\frac{x}{3}-\frac{1}{4}=-\frac{5}{6}\Leftrightarrow\frac{x}{3}+\frac{7}{12}=0\Leftrightarrow\frac{4x}{12}+\frac{7}{12}=0\)

Khử mẫu ta đc : \(4x+7=0\Leftrightarrow4x=-7\Leftrightarrow x=-\frac{7}{4}\)

b, \(\frac{x+3}{15}=\frac{1}{3}\Leftrightarrow\frac{x+3}{15}=\frac{5}{15}\)

Khử mẫu ta đc : \(x+3=5\Leftrightarrow x=2\)

a) \(\frac{x-3}{3}-1=\frac{x}{-4}\)

\(\Leftrightarrow\frac{x-3}{3}-\frac{3}{3}=\frac{x}{-4}\)

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

\(\Leftrightarrow-4\left(x-6\right)=3x\)

\(\Leftrightarrow-4x+24=3x\)

\(\Leftrightarrow24=3x+4x\)

\(\Leftrightarrow7x=24\)

\(\Leftrightarrow x=\frac{24}{7}\)

b) \(\frac{5}{8}-\left(x-\frac{1}{2}\right)=\frac{-3}{4}\)

\(\Leftrightarrow\frac{5}{8}-x+\frac{1}{2}=\frac{-3}{4}\)

\(\Leftrightarrow\frac{5}{8}+\frac{4}{8}-x=\frac{-3}{4}\)

\(\Leftrightarrow\frac{9}{8}-x=\frac{-3}{4}\)

\(\Leftrightarrow x=\frac{9}{8}+\frac{3}{4}\)

\(\Leftrightarrow x=\frac{15}{8}\)

Bài 1: so sánh

A = \(\frac56\) x \(\frac43\) x \(\frac{-12}{15}\)

A = \(\frac{5}{15}\) x \(-\frac{12}{6}\) x \(\frac43\)

A = -\(\frac13\) x 2 x \(\frac43\)

A = - \(\frac89\)

B = - \(\frac{4}{14}\) x \(\frac63\) x \(\frac{7}{18}\)

B = - \(\frac{4}{18}\) x ( \(\frac63\) x \(\frac{7}{14}\))

B = - \(\frac29\) x 1

B = - 2/9

8/9 > 2/9

- 8/9 < -2/9

Vậy A < B

Bài 1: So sánh:

H = (3/4 - 4/5) x (-20)

H = (15/20 - 16/20) x (-20)

H = -1/20 x (-20)

H = 1

K = (3/2 - 3/5) - 10/4

K = 30/20 - 12/20 - 50/20

K = 18/20 - 50/20

K = - 32/20

K = - 8/5 < 1

Vậy H > K

x/15 = 3/5 + -2/3

Quy đồng

3/5 = 9/15 ; -2/3 = -10/15

=> x = -10

Ủng hộ nhé ! Bấm Đúng nếu thấy mình trả lời đúng ! 

Cự Giải thì cũng k và kết bạn nhé !