Question 1152109
Let {{{ p }}} = number of pennies
Let {{{ d }}} = number of dimes
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(1) {{{ p + d = 50 }}}
(2) {{{ p = 4d }}}
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Plug (2) into (1)
(1) {{{ 4d + d = 50 }}}
(1) {{{ 5d = 50 }}}
(1) {{{ d = 10 }}}
and
(2) {{{ p = 4*10 }}}
(2) {{{ p = 40 }}}
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She has 40 pennies