Question

\(\text{Tìm x, biết:}\)

\(a\)) \(20\text{%}x-x+\dfrac{1}{5}=\dfrac{3}{4}\)

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

\(c\)) \(\left(x-\dfrac{3}{4}\right)\left(4+3x\right)=0\)

\(d\)) \(x-\dfrac{1}{3}x+\dfrac{1}{5}x=\dfrac{-26}{5}\)

\(e\)) \(50\text{%}x+\dfrac{2}{3}x=x-5\)

\(g\)) \(\dfrac{2}{3}\left(x+\dfrac{9}{5}\right)-\dfrac{3}{10}.\left(5x-\dfrac{1}{3}\right)=\dfrac{7}{15}\)

Answer 1

câu c) mang tính mua vui hay gì hả bn

Answer 2

mếu thật thì x=0,x=số nào cx đc(câu trả lời này mang tính mua vui thôi nhé)

Answer 3

Answer 4

a) Ta có: \(20\%x-x+\dfrac{1}{5}=\dfrac{3}{4}\)

\(\Leftrightarrow\dfrac{-4}{5}x=\dfrac{3}{4}-\dfrac{1}{5}=\dfrac{11}{20}\)

hay \(x=-\dfrac{11}{16}\)

Vậy: \(x=-\dfrac{11}{16}\)

Answer 5

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

\(\Leftrightarrow2\left(2x+1\right)=3\left(x-5\right)\)

\(\Leftrightarrow4x+2=3x-15\)

\(\Leftrightarrow4x-3x=-15-2\)

hay x=-17

Vậy: x=-17

Answer 6

c) Ta có: \(\left(x-\dfrac{3}{4}\right)\left(4+3x\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x-\dfrac{3}{4}=0\\3x+4=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{3}{4}\\x=-\dfrac{4}{3}\end{matrix}\right.\)

Vậy: \(x\in\left\{\dfrac{3}{4};-\dfrac{4}{3}\right\}\)

Answer 7

d) Ta có: \(x-\dfrac{1}{3}x+\dfrac{1}{5}x=\dfrac{-26}{5}\)

\(\Leftrightarrow x\left(1-\dfrac{1}{3}+\dfrac{1}{5}\right)=-\dfrac{26}{5}\)

\(\Leftrightarrow x\cdot\dfrac{13}{15}=\dfrac{-26}{5}\)

hay \(x=-6\)

Vậy: x=-6

Answer 8

e) Ta có: \(50\%\cdot x+\dfrac{2}{3}x=x-5\)

\(\Leftrightarrow\dfrac{7}{6}x-x=-5\)

\(\Leftrightarrow\dfrac{1}{6}x=-5\)

hay x=-30

Vậy: x=-30

Answer 9

g) Ta có: \(\dfrac{2}{3}\left(x+\dfrac{9}{5}\right)-\dfrac{3}{10}\left(5x-\dfrac{1}{3}\right)=\dfrac{7}{15}\)

\(\Leftrightarrow\dfrac{2}{3}x+\dfrac{6}{5}-\dfrac{3}{2}x+\dfrac{1}{10}=\dfrac{7}{15}\)

\(\Leftrightarrow\dfrac{-5}{6}x=-\dfrac{5}{6}\)

hay x=1

Vậy: x=1