Question 730921
Let {{{ a }}} = ounces of the 1st mixture needed
Let {{{ b }}} = ounces of the 2nd mixture needed
{{{ .25a }}} = ounces of almonds in 1st mixture
{{{ .55b }}} = ounces of almonds in 2nd mixture
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{{{ b = a + 37 }}}
{{{ ( .25a + .55b ) / ( a + b ) = .43 }}}
{{{ .25a + .55b = .43*( a + b ) }}}
{{{ .25a + .55b = .43a + .43b ) }}} 
By substitution:
{{{ .25a + .55*( a + 37 ) = .43a + .43*( a + 37 ) }}}
{{{ .25a + .55a + 20.35 = .43a + .43a + 15.91 }}}
{{{ .8a + 20.35 = .86a + 15.91 }}}
{{{ .06a = 4.44 }}}
{{{ a = 74 }}}
and 
{{{ b = a + 37 }}}
{{{ b = 111 }}}
74 ounces of the 1st mixture is needed
111 ounces of the 2nd mixture is needed
check:
{{{ ( .25a + .55b ) / ( a + b ) = .43 }}}
{{{ ( .25*74 + .55*111 ) / ( 74 + 111 ) = .43 }}}
{{{ ( 18.5 + 61.05 ) / 185 = .43 }}}
{{{ 79.55 = .43*185 }}}
{{{ 79.55 = 79.55 }}}
OK