Question 940205
Bob sold a total of {{{ 995 - 395 = 600 }}}
Let {{{ a }}} = number of cheese pizzas sold
Let {{{ b }}} = number of pepperoni pizzas sold
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(1) {{{ a + b = 600 }}}
(2) {{{ 5a + 9b = 4560 }}}
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Multiply both sides of (1) by 
{{{ 5 }}} and subtract (1) from (2)
(2) {{{ 5a + 9b = 4560 }}}
(1) {{{ -5a - 5b = - 3000 }}}
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{{{ 4b = 1560 }}}
{{{ b = 390 }}}
and
(1) {{{ a + 390 = 600 }}}
(1) {{{ a = 210 }}}
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210 cheese pizzas were sold
390 pepperoni pizzas were sold