Question

Tìm x,biết:

a/ \(\frac{x}{3}-\frac{10}{21}=\frac{-1}{7}\)

b/x-25%=\(\frac{1}{2}\)

c/ \(\frac{-5}{6}+\frac{8}{3}+\frac{-29}{6}\le x\le\frac{-1}{2}+2+\frac{5}{2}\)

Answer 1

a) \(\frac{x}{3}-\frac{10}{21}=-\frac{1}{7}\)

\(\Rightarrow\frac{x}{3}=-\frac{1}{7}+\frac{10}{21}\)

\(\Rightarrow\frac{x}{3}=\frac{7}{21}\)

\(\Rightarrow\frac{x}{3}=\frac{1}{3}\)

\(\Rightarrow x=1\)

\(x-25\%=\frac{1}{2}\)

\(\Rightarrow x-\frac{1}{4}=\frac{1}{2}\)

\(\Rightarrow x=\frac{1}{2}+\frac{1}{4}\)

\(\Rightarrow x=\frac{3}{4}\)

c) \(-\frac{5}{6}+\frac{8}{3}+-\frac{29}{6}\le x\le-\frac{1}{2}+2+\frac{5}{2}\)

\(\Rightarrow-3\le x\le4\)

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

Answer 2

a)x/3-10/21=-1/7

 x/3=-1/7+10/21

x/3=1/3

=> x= 1

   

Answer 3

b/ x-25%=1/2

      x-1/4=1/2

             x=1/2+1/4

             x=3/4