Question 916512
Let {{{ a }}} = number of bowls
Let {{{ b }}} = number of plates
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(1) {{{ a + b = 20 }}}
(2) {{{ 4.5a + 6b = 96 }}}
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(2) {{{ 45a + 60b = 960 }}}
(2) {{{ 9a + 12b = 192 }}}
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Multiply both sides of (1) by {{{ 9 }}}
and subtract (1) from (2)
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(2) {{{ 9a + 12b = 192 }}}
(1) {{{ -9a - 9b = -180 }}}
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{{{ 3b = 12 }}}
{{{ b = 4 }}}
and, since
(1) {{{ a + b = 20 }}}
(1) {{{ a = 16 }}}
She has 16 bowls and 4 plates
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check:
(2) {{{ 4.5*16 + 6*4 = 96 }}}
(2) {{{ 72 + 24 = 96 }}}
(2) {{{ 96 = 96 }}}
OK