Question 967352
Let {{{ a }}} = pounds of cashews added
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{{{ ( 3*20 + 5a ) / ( 20 + a ) = 3.5 }}}
{{{ 60 + 5a = 3.5*( 20 + a ) }}}
{{{ 60 + 5a = 70 + 3.5a }}}
{{{ 1.5a = 10 }}}
{{{ a = 6.667 }}}
6.667 pounds of cashews are needed
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check:
{{{ ( 3*20 + 5a ) / ( 20 + a ) = 3.5 }}}
{{{ ( 3*20 + 5*6.667 ) / ( 20 + 6.667 ) = 3.5 }}}
{{{ ( 60 + 33.333 ) / 26.667 = 3.5 }}}
{{{ 93.333 / 26.667 = 3.5 }}}
{{{ 93.333 = 3.5*26.667 }}}
{{{ 93.333 = 93.333 }}}