K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

a: \(\Leftrightarrow70+18< x< 120+126+70\)

=>88<x<316

hay \(x\in\left\{89;90;...;315\right\}\)

b: \(\Leftrightarrow-\dfrac{9}{3}< x< \dfrac{8}{5}+\dfrac{9}{5}=\dfrac{17}{5}\)

=>-3<x<3,4

hay \(x\in\left\{-2;-1;0;1;2;3\right\}\)

a: \(\Leftrightarrow-\dfrac{720}{150}=-4.8< x< \dfrac{-63}{210}=-0.3\)

mà x là số nguyên

nen \(x\in\left\{-4;-3;-2;-1\right\}\)

b: \(\Leftrightarrow-\dfrac{125}{27}< x< \dfrac{120}{210}=\dfrac{4}{7}\)

mà x là số nguyên

nên \(x\in\left\{-4;-3;-2;-1;0\right\}\)

15 tháng 5 2017

Trả lời

undefined

15 tháng 5 2017

Trả lời:

undefined

a: \(\Leftrightarrow\dfrac{1}{2}-\dfrac{1}{3}-\dfrac{1}{4}< x< \dfrac{1}{48}-\dfrac{1}{16}+\dfrac{1}{6}\)

\(\Leftrightarrow\dfrac{6}{12}-\dfrac{4}{12}-\dfrac{3}{12}< x< \dfrac{1}{48}-\dfrac{3}{48}+\dfrac{8}{48}\)

\(\Leftrightarrow\dfrac{-1}{12}< x< \dfrac{1}{8}\)

\(\Leftrightarrow-2< 24x< 3\)

=>x=0

b: \(\Leftrightarrow\dfrac{9-10}{12}< \dfrac{x}{12}< 1-\dfrac{8-3}{12}=\dfrac{7}{12}\)

=>-1<x<7

hay \(x\in\left\{0;1;2;3;4;5;6\right\}\)

27 tháng 3 2017

A=\(\dfrac{2}{7}+\dfrac{-3}{8}+\dfrac{11}{7}+\dfrac{1}{3}+\dfrac{1}{7}+\dfrac{5}{-3}\)

A=\(\left(\dfrac{2}{7}+\dfrac{11}{7}+\dfrac{1}{7}\right)+\left(\dfrac{1}{3}+\dfrac{5}{-3}\right)+\dfrac{-3}{8}\)

A=\(2+\dfrac{-4}{3}+\dfrac{-3}{8}\)

A=\(\dfrac{7}{24}\)

B=\(\dfrac{3}{17}+\dfrac{-5}{13}+\dfrac{-18}{35}+\dfrac{14}{17}+\dfrac{17}{-35}+\dfrac{-8}{13}\)

B=\(\left(\dfrac{3}{17}+\dfrac{14}{17}\right)+\left(\dfrac{-18}{35}+\dfrac{17}{-35}\right)+\left(\dfrac{-5}{13}+\dfrac{-8}{13}\right)\)

B=\(\dfrac{17}{17}+\dfrac{-35}{35}+\dfrac{-13}{13}\)

B=\(1+\left(-1\right)+\left(-1\right)=-1\)

C=\(\dfrac{-3}{17}+\left(\dfrac{2}{3}+\dfrac{3}{17}\right)\)

C=\(\dfrac{-3}{17}+\dfrac{2}{3}+\dfrac{3}{17}=\left(\dfrac{-3}{17}+\dfrac{3}{17}\right)+\dfrac{2}{3}\)

C=0+\(\dfrac{2}{3}=\dfrac{2}{3}\)

D=\(\left(\dfrac{-1}{6}+\dfrac{5}{-12}\right)+\dfrac{7}{12}\)

D=\(\dfrac{-1}{6}+\dfrac{5}{-12}+\dfrac{7}{12}\)

D=\(\dfrac{-2}{12}+\dfrac{-5}{12}+\dfrac{7}{12}=\left(\dfrac{-2}{12}+\dfrac{-5}{12}\right)+\dfrac{7}{12}\)

D=\(\dfrac{-7}{12}+\dfrac{7}{12}=0\)

7 tháng 3 2017

bạn cứ tính 2 vế là xong mà:

a) x\(\in\){1;2;3;4;5;6;7}

b) x=0

11 tháng 7 2017

giúp zới

khocroi

https://i.imgur.com/7ARysDs.jpg

Tặng kèm nèèèèèèè!!!!!!!!!!!!

10 tháng 3 2018

Ta có: 1/3 + −2/5+ 1/6 + −1/5 ≤ x < −3/4+2/7+-1/4+3/5+5/7

⇒10-12+5-6/30≤ x< -105+40-35+84+100/140

⇒-3/30≤ x <84/140

⇒-0,1≤ x < 0,6

⇒x=0

a: \(\dfrac{x+2}{27}=\dfrac{x}{-9}\)

=>x+2=-3x

=>4x=-2

hay x=-1/2

b: \(\dfrac{-7}{x}=\dfrac{21}{34-x}\)

=>-7(34-x)=21x

=>34-x=-3x

=>2x=-34

hay x=-17

c: \(\dfrac{-8}{15}< \dfrac{x}{40}< \dfrac{-7}{15}\)

\(\Leftrightarrow-64< 3x< -56\)

hay \(x\in\left\{-21;-20;-19\right\}\)

d: \(\dfrac{-1}{2}< \dfrac{x}{18}< \dfrac{-1}{3}\)

=>-9<x<-6

hay \(x\in\left\{-8;-7\right\}\)