\(\Rightarrow\dfrac{-6}{x}=\dfrac{1}{2}\)

\(\Rightarrow x=-12\)

-12

a: =>x/10=-22/10

hay x=-22

b: =>-6/x=6/12

=>x=-12

\(a,\dfrac{x}{10}=\dfrac{-11}{5}\Rightarrow x.5=10.\left(-11\right)=-110\\ \Rightarrow-22\\ b,\dfrac{-6}{x}=\dfrac{30}{60}\Rightarrow-6.60=x.30=-120\\ \Rightarrow x=-4\)

a) x=\(\dfrac{5.6}{-10}=-3.\)

b) y=\(\dfrac{3.77}{-33}=-7.\)

x=-3

y=-7

ĐS. a) b) x = 1.

a) x.21=6.7

x.21=42

x=42:21

x = 2

b) y . 20 = -5.28

y.20 = -140

y = (-140) : 20

y = -7

a)=>x*21=7*6

=>x*21=42

=>x=42/21

x=2

b)=>y*20=(-5)*28

=>y*20=-140

=>y=-140/20

y=-7

4\(\dfrac{1}{3}.\left(\dfrac{1}{6}-\dfrac{1}{2}\right)\)\(\le x\le\dfrac{2}{3}.\left(\dfrac{1}{3}-\dfrac{1}{2}-\dfrac{3}{4}\right)\)

\(\dfrac{-13}{9}\le x\le\dfrac{-11}{12}\)

\(\dfrac{-468}{36}\le\dfrac{36.x}{36}\le\dfrac{-396}{36}\)

\(=>36.x\in\left\{-467;-466;-465;-464;...;-398;-397\right\}\)

\(=>x=-12\)

a, \(\dfrac{3}{x}+\dfrac{y}{3}=\dfrac{5}{6}\)

ta có: \(\dfrac{3}{x}+\dfrac{y}{3}=\dfrac{5}{6}=>\dfrac{3}{x}=\dfrac{5}{6}-\dfrac{y}{3}=\dfrac{5-2y}{6}\)

=>\(\dfrac{3}{x}=\dfrac{5-2y}{6}=>x.\left(5-2y\right)=3.6=18\)

=> x và 5-2y thuộc Ư của 18={1,-1,2,-2,3,-3,6,-6}

vì 5-2y là số lẻ=> 5-2y= +-1 hoặc 5-2y=+-3

xét bảng

vậy giá trị x,y cần tìm là: {x=18.y=2}

{x=-18.y=3}

{x=6, y=1}Ư

{x=-6,y=4}

a, \(\dfrac{x}{5}=\dfrac{-19}{30}+\dfrac{5}{6}\)

\(\Rightarrow\dfrac{x}{5}=\dfrac{1}{5}\)

\(\Rightarrow x=1\)

b, \(\dfrac{6}{7}+\dfrac{5}{7}:x=\dfrac{8}{9}\)

\(\Rightarrow\dfrac{5}{7}:x=\dfrac{8}{9}-\dfrac{6}{7}\)

\(\Rightarrow\dfrac{5}{7}:x=\dfrac{2}{63}\)

\(\Rightarrow x=\dfrac{5}{7}:\dfrac{2}{63}\)

\(\Rightarrow x=\dfrac{45}{2}\)

thiếu trầm trọng Thiên Phong

\(\dfrac{-5}{6}\)- x=\(\dfrac{7}{12}\)+\(\dfrac{-8}{12}\)=\(\dfrac{-15}{12}\)

\(\Rightarrow\)x=\(\dfrac{-5}{6}\)-\(\dfrac{-15}{12}\)=\(\dfrac{-10}{12}\)-\(\dfrac{-15}{12}\)=\(\dfrac{-25}{12}\)

Em vào ib chị xíu