Question 1009737
Let {{{ n }}} = numbe of nickels
Let {{{ d }}} = number of dimes
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(1) {{{ n + d = 66 }}}
(2) {{{ 5n + 10d = 440 }}} ( in cents )
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This is 2 equations and 2 unknowns,
so it's solvable
(2) {{{ n + 2d = 88 }}}
Subtract (1) from (2)
(2) {{{ n + 2d = 88 }}}
(1) {{{ -n - d = -66 }}}
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{{{ d = 22 }}}
and
(1) {{{ n + d = 66 }}}
(1) {{{ n +22 = 66 }}}
(1) {{{ n = 44 }}}
There are 44 nickels and 22 dimes
check:
(2) {{{ 5n + 10d = 440 }}}
(2) {{{ 5*44 + 10*22 = 440 }}}
(2) {{{ 220 + 220 = 440 }}}
(2) {{{ 440 = 440 }}}
OK