Question 1147770
Let {{{ a }}} = number of $15 tickets sold
Let {{{ b }}} = number of $25 tickets sold
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(1) {{{ a + b = 8600 }}}
(2) {{{ 15a + 25b = 178000 }}}
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(2) {{{ 3a + 5b = 35600 }}}
Multiply both sides of (1) by {{{5}}}
and subtract (2) from (1)
(1) {{{ 5a + 5b = 43000 }}}
(2) {{{ -3a - 5b = - 35600 }}}
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{{{ 2a = 7400 }}}
{{{ a = 3700 }}}
and
(1) {{{ 3700 + b = 8600 }}}
(1) {{{ b = 4900 }}}
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3700 $15 tickets sold
4900 $25 tickets sold
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check:
(2) {{{ 15a + 25b = 178000 }}}
(2) {{{ 15*3700 + 25*4900 = 178000 }}}
(2) {{{ 55500 + 122500 = 178000 }}}
(2) {{{ 178000 = 178000 }}}
OK