Question 714744
Let {{{ x }}} gallons = a full tank
{{{ (3/8)*x + 6 = (3/4)*x }}}
Multiply both sides by {{{ 8 }}}
{{{ 3x + 48 = 6x }}}
{{{ 3x = 48 }}}
{{{ x = 16 }}}
The tank holds 16 gallons
check:
3/8 full is {{{ (3/8)*16 = 6 }}} gallons
then, he buys 6 gallons
{{{ 6 + 6 = 12 }}}
and 12 is 3/4 of a full tank
{{{ (3/4)*16 = 12 }}}
{{{ 12 = 12 }}}
OK