Question

tìm x,biết:

a)\(\frac{3}{35}-\left(\frac{3}{5}+x\right):\frac{2}{7}=\frac{2}{7}\)

b)\(\left(5x-1\right)\left(2x-\frac{1}{3}\right)=0\)

c)\(\frac{3}{7}+\frac{1}{7}:x=\frac{3}{14}\)

Answer 1

a.\(\Rightarrow\left(\frac{3}{5}+x\right):\frac{2}{7}=\frac{3}{35}-\frac{2}{7}\)

\(\Rightarrow\left(\frac{3}{5}+x\right):\frac{2}{7}=-\frac{1}{5}\)

\(\Rightarrow\frac{3}{5}+x=-\frac{1}{5}.\frac{2}{7}\)

\(\Rightarrow\frac{3}{5}+x=-\frac{2}{35}\)

\(\Rightarrow x=-\frac{2}{35}-\frac{3}{5}\)

Vậy \(x=-\frac{23}{35}\).

b. => 5x-1=0                hoặc 2x-1/3=0

=> 5x=1                       hoặc 2x=1/3

=> x=1/5                      hoặc x=1/6

c. \(\Rightarrow\frac{1}{7}:x=\frac{3}{14}-\frac{3}{7}\)

\(\Rightarrow\frac{1}{7}:x=-\frac{3}{14}\)

\(\Rightarrow x=\frac{1}{7}:\left(-\frac{3}{14}\right)\)

Vậy \(x=\frac{-2}{3}\).