Question

[lưu trâm]

Giúp mik với ạ!!

7. Tìm x ϵ Z, biết:

a) \(\dfrac{-5}{19}\) + \(\dfrac{2}{19}\) < \(\dfrac{x}{19}\) ≤ \(\dfrac{17}{19}\) - \(\dfrac{16}{19}\)

b) \(\dfrac{4}{5}\) + \(\dfrac{-5}{6}\) ≤ \(\dfrac{x}{30}\) ≤ \(\dfrac{-3}{10}\) + \(\dfrac{1}{3}\)

Mik cảm ơn nhìu

Answer 1

[Nguyễn Lê Phước Thịnh]

a: \(\dfrac{-5}{19}+\dfrac{2}{19}< \dfrac{x}{19}< =\dfrac{17}{19}-\dfrac{16}{19}\)

=>\(\dfrac{-3}{19}< \dfrac{x}{19}< =\dfrac{1}{19}\)

=>-3<x<=1

mà x nguyên

nên \(x\in\left\{-2;-1;0;1\right\}\)

b: \(\dfrac{4}{5}+\dfrac{-5}{6}< =\dfrac{x}{30}< =\dfrac{-3}{10}+\dfrac{1}{3}\)

=>\(\dfrac{24-25}{30}< =\dfrac{x}{30}< =\dfrac{-9+10}{30}\)

=>\(-1< =x< =1\)

mà x nguyên

nên \(x\in\left\{-1;0;1\right\}\)