Question 599426
Let {{{ a }}} = dollars invested @ 1%
Let {{{ b }}} = dollars invested @ 6%
{{{ .01a + .06b = 17.68 }}}
{{{ .01b + .06a = 14.04 }}}
and
{{{ a + 6b = 1768 }}}
{{{ b + 6a = 1404 }}}
and
(1) {{{ a + 6b = 1768 }}}
(2) {{{ 6a + b = 1404 }}}
Multiply both sides of (2) by {{{ 6 }}}
and subtract (1) from (2)
(2) {{{ 36a + 6b = 8424 }}}
(1) {{{ -a - 6b = -1768 }}}
{{{ 35a = 6656 }}}
{{{ a = 190.1714 }}}
and
(2) {{{ 6*190.1714 + b = 1404 }}}
(2) {{{ 1141.0285 + b = 1404 }}}
(2) {{{ b = 262.9715 }}}
Mary invested $190.17 @ 1% and
$262.97 @ 6%