Question

tìm x thuộc z:

a 5x(1/4-1/5-1/10) bé hơn hoặc = x/20 < hoặ = -3x(1/2-1/4-1/5)

Answer 1

Sửa đề lại :

Tìm x thuộc Z

\(5\times\left[\frac{1}{4}-\frac{1}{5}-\frac{1}{10}\right]\le\frac{x}{20}\le-3\times\left[\frac{1}{2}-\frac{1}{4}-\frac{1}{5}\right]\)

\(\Leftrightarrow5\times\left[\frac{5}{20}-\frac{4}{20}-\frac{2}{20}\right]\le\frac{x}{20}\le-3\times\left[\frac{10}{20}-\frac{5}{20}-\frac{4}{20}\right]\)

\(\Leftrightarrow5\times\frac{-1}{20}\le\frac{x}{20}\le-3\times\frac{1}{20}\)

\(\Leftrightarrow\frac{-5}{20}\le\frac{x}{20}\le\frac{-3}{20}\)

\(\Leftrightarrow-5\le x\le-3\)

\(\Leftrightarrow x\in\left\{-5;-4;-3\right\}\)

Study well >_<

Answer 2

bn lm câu nafycho mk luôn

(3/5--4/5)x60<x<3/7x(5/6-2+7/2)

Answer 3

mk đag caaffn gấp lm í