Question 54786
{{{ 3x/7 - 5x/3 = 2/21 }}}
Since the denominators of all three fractions are factors of 21, multiply each one by 21 
{{{ (21)3x/7 - (21)5x/3 = (21)2/21 }}}
reduce the fractions
{{{ 9x - 35x = 2 }}}
Combine like terms
{{{ -26x =2 }}}
divide by -26
{{{ x = -2/26 }}}
reduce
{{{ x = -1/13 }}}