Question 459256
Let {{{a}}} = amount invested @ 8%
Let {{{b}}} = amount invested @ 6%
given:
(1) {{{ .08a + .06b = 3600 }}}
(1) {{{ 8a + 6b = 360000 }}}
and
(2) {{{ a + b = 50000 }}}
Multiply both sides of (2) by {{{6}}}
and subtract (2) from (1)
(1) {{{ 8a + 6b = 360000 }}}
(2) {{{ -6a - 6b = -300000 }}}
{{{ 2a = 60000 }}}
{{{ a = 30000 }}}
and, since
(2) {{{ a + b = 50000 }}}
{{{ b = 20000 }}}
$30,000 = amount invested @ 8%
$20,000 = amount invested @ 6%
check answer:
(1) {{{ .08a + .06b = 3600 }}}
(1) {{{ .08*30000 + .06*20000 = 3600 }}}
(1) {{{ 2400 + 1200 = 3600 }}}
(1) {{{ 3600 = 3600 }}}
OK