Question 542361
given:
(1) {{{ x + y = 17 }}}
(2) {{{ 5x + 10y = 110 }}} ( in cents)
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Multiply both sides of (1) by {{{5}}}
and subtract (1) from (2)
(2) {{{ 5x + 10y = 110 }}}
(1) {{{ -5x - 5y = -85 }}}
{{{ 5y = 25 }}}
{{{ y = 5 }}}
and, since
(1) {{{ x + y = 17 }}}
(1) {{{ x + 5 = 17 }}}
(1) {{{ x = 12 }}}
There are 12 nickels and 5 dimes