Question 498791
Let {{{a}}} = amount invested @ 3.5%
Let {{{b}}} = amount invested @ 5%
given:
(1) {{{ a + b = 2000 }}}
(2) {{{ .035a + .05b = 84.25 }}}
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Multiply both sides of (2) by {{{ 1000 }}}
(2) {{{ 35a + 50b = 84250 }}}
Multiply both sides of (1) by {{{ 35 }}}
and subtract (1) from (2)
(2) {{{ 35a + 50b = 84250 }}}
(1) {{{ -35a - 35b = -70000 }}}
{{{ 15b = 14250 }}}
{{{ b = 950 }}}
and, since
(1) {{{ a + b = 2000 }}}
(1) {{{ a + 950 = 2000 }}}
(1) {{{ a = 1050 }}}
$1,050 = amount invested @ 3.5%
$950 = amount invested @ 5%
check:
(2) {{{ .035a + .05b = 84.25 }}}
(2) {{{ .035*1050 + .05*950 = 84.25 }}}
(2) {{{ 36.75 + 47.5 = 84.25 }}}
(2) {{{ 84.25 = 84.25 }}}
OK