Giải các phương trình sau :
a) \(\frac{2x-1}{5}\)- \(\frac{x-2}{3}\)= \(\frac{x+7}{15}\)
b) \(\frac{2\left(x+5\right)}{3}\)+ \(\frac{x+12}{2}\)- \(\frac{5\left(x-2\right)}{6}\)= \(\frac{x}{3}\)+ 11
c) \(\frac{2\left(x-3\right)}{7}\)+ \(\frac{x-5}{3}\)= \(\frac{13x+4}{21}\)
d) \(\frac{x+3}{2}\)- \(\frac{x-1}{3}\)= \(\frac{x+5}{6}\)+ 1
e) \(\frac{x-4}{5}\)+ \(\frac{3x-2}{10}\)- x = \(\frac{2x-5}{3}\)- \(\frac{7x+2}{6}\)
f) \(\frac{3x-1}{2}\)- \(\left(x-\frac{1}{4}\right)\)= \(\frac{4x-9}{8}\)
\(\frac{2x-1}{5}-\frac{x-2}{3}=\frac{x+7}{15}\)
<=> \(\frac{2x-1}{5}-\frac{x-2}{3}-\frac{x+7}{15}=0\)
<=> \(\frac{3\left(2x-1\right)}{5\cdot3}-\frac{5\left(x-2\right)}{3\cdot5}-\frac{x+7}{15}=0\)
<=> \(\frac{6x-3-5x+10-x-7}{15}=0\)
<=> \(\frac{-14}{15}=0\)
=> PT vô nghiệm