Question 923639
( natural oil ) / ( synthetic oil ) = {{{ 5/8 }}}
Let {{{ x }}} = liters of synthetic oil needed
{{{ 936 - x }}} = liters of natural oil needed
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{{{ 5/8 = ( 936 - x ) / x }}}
Multiply both sides by {{{ 8x }}}
{{{ 5x = 8*( 936 - x ) }}}
{{{ 5x = 7488 - 8x }}}
{{{  13x = 7488 }}}
{{{ x = 576 }}}
576 liters of synthetic oil are needed
check:
{{{ 5/8 = ( 936 - x ) / x }}}
{{{ 5/8 = ( 936 - 576 ) / 576 }}}
{{{ 5/8 = 360/576 }}}
{{{ .625 = .625 }}}
OK