Question 1129052
Let {{{ a }}} = the price of an adult ticket
Let {{{ b }}} = the price of a child's ticket
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(1) {{{ 3a + 4b = 80 }}}
(2) {{{ 2a + 3b = 57 }}}
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Multiply both sides of (1) by {{{ 2 }}}
Multiply both sides of (2) by {{{ 3 }}}
Subtract (1) from (2)
(2) {{{ 6a + 9b = 171 }}}
(1) {{{ -6a - 8b = -160 }}}
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{{{ b = 11 }}}
and
(2) {{{ 2a + 33 = 57 }}}
(2) {{{ 2a = 24 }}}
(2) {{{ a = 12 }}}
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An adult ticket is $12
A child's ticket is $11
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check:
(1) {{{ 3*12 + 4*11 = 80 }}}
(1) {{{ 36 + 44 = 80 }}}
(1) {{{ 80 = 80 }}}
OK