Question

Tìm x :

a) \(\dfrac{5}{3}+1\dfrac{1}{3}< x< 3\dfrac{1}{5}+1\dfrac{8}{10}\)

b) \(\dfrac{-1}{4}+\dfrac{1}{3}:2x=-5\)

c) \(\dfrac{-3}{2}x+\dfrac{6}{7}=\dfrac{10}{3}\)

d) \(\dfrac{1}{3}+\dfrac{3}{35}< \dfrac{x}{210}< \dfrac{4}{7}+\dfrac{1}{3}\)

Answer 1

a: \(\Leftrightarrow\dfrac{5}{3}+\dfrac{4}{3}< x< 3+\dfrac{1}{5}+1+\dfrac{4}{5}\)

=>3<x<5

=>x=4

b: \(\Leftrightarrow\dfrac{1}{3}:2x=-5+\dfrac{1}{4}=-\dfrac{19}{4}\)

=>\(2x=\dfrac{1}{3}:\dfrac{-19}{4}=\dfrac{1}{3}\cdot\dfrac{-4}{19}=\dfrac{-4}{57}\)

=>x=-2/57

c: \(\Leftrightarrow x\cdot\dfrac{-3}{2}=\dfrac{10}{3}-\dfrac{6}{7}=\dfrac{70-18}{21}=\dfrac{52}{21}\)

=>\(x=\dfrac{-52}{21}:\dfrac{3}{2}=\dfrac{-52}{21}\cdot\dfrac{2}{3}=\dfrac{-104}{63}\)

d: \(\Leftrightarrow70+18< x< 120+70\)

=>88<x<190

hay \(x\in\left\{89;90;...;188;189\right\}\)