Question 624537
Let {{{ n }}} = number of nickels
Let {{{ q }}} = number of quarters
given:
(1) {{{ n = q - 5 }}}
(2) {{{ 5n + 25q = 485 }}} ( in cents )
substitute (1) into (2)
(2) {{{ 5*( q - 5 ) + 25q = 485 }}}
(2) {{{ 5q - 25 + 25q = 485 }}}
(2) {{{ 30q = 510 }}}
(2) {{{ q = 17 }}}
and
(1) {{{ n = q - 5 }}}
(1) {{{ n = 17 - 5 }}}
(1) {{{ n = 12 }}}
she has 12 nickels and 17 quarters
check answer:
(2) {{{ 5n + 25q = 485 }}}
(2) {{{ 5*12 + 25*17 = 485 }}}
(2) {{{ 60 + 425 = 485 }}}
(2) {{{ 485 = 485 }}}
OK