Question 1089633
Let {{{ n }}} = number of nickels
Let {{{ q }}} = number of quarters
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(1) {{{ 5n + 25q = 305 }}}
(2) {{{ n = q + 7 }}}
Plug (2) into (1)
(1) {{{ 5*( q+7 ) + 25q = 305 }}}
(1) {{{ 5q + 35 + 25q = 305 }}}
(1) {{{ 30q = 270 }}}
(1) {{{ q = 9 }}}
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and
(2) {{{ n = q + 7 }}}
(2) {{{ n = 9 + 7 }}}
(2) {{{ n = 16 }}}
There are 16 nickels and 9 quarters
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check:
(1) {{{ 5n + 25q = 305 }}}
(1) {{{ 5*16 + 25*9 = 305 }}}
(1) {{{ 80 + 225 = 305 }}}
(1) {{{ 305 = 305 }}}
OK