Question 1094639
Let {{{ n }}} = number of nickels
Let {{{ d }}} = number of dimes
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(1) {{{ 5n + 10d = 85 }}}
(2) {{{ d = n + 4 }}}
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Substitute (2) into (1)
(1) {{{ 5n + 10*( n + 4 ) = 85 }}}
(1) {{{ 5n + 10n + 40 = 85 }}}
(1) {{{ 15n = 45 }}}
(1) {{{ n = 3 }}}
and
(2) {{{ d = n + 4 }}}
(2) {{{ d = 3 + 4 }}}
(2) {{{ d = 7 }}}
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There are 3 nickels and 7 dimes
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check:
(1) {{{ 5n + 10d = 85 }}}
(1) {{{ 5*3 + 10*7 = 85 }}}
(1) {{{ 15 + 70 = 85 }}}
(1) {{{ 85 + 85 }}}
OK