Question 596151
Let {{{ a }}} = the cost of an adult ticket
Let {{{ s }}} = the cost of a student ticket
given:
(1) {{{ 3a + 4s = 84 }}}
(2) {{{ 4a + 2s = 62 }}}
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Multiply both sides of (2) by {{{ 2 }}}
and subtract (1) from (2)
(2) {{{ 8a + 4s = 124 }}}
(1) {{{ -3a - 4s = -84 }}}
{{{ 5a = 40 }}}
{{{ a = 8 }}}
and, since
(2) {{{ 4a + 2s = 62 }}}
(2) {{{ 32 + 2s = 62 }}}
(2) {{{ 2s = 30 }}}
(2) {{{ s = 15 }}}
An adult ticket is $8
A student ticket is $15
check:
(1) {{{ 3*8 + 4*15 = 84 }}}
(1) {{{ 24 + 60 = 84 }}}
(1) {{{ 84 = 84 }}}
OK