Question 1047197
Let {{{ a }}} = pounds of type A coffee needed
Let {{{ b }}} = pounds of type B coffee needed
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(1) {{{ a + b = 179 }}}
(2) {{{ 4.65a + 5.95b = 955.85 }}}
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(2) {{{ 465a + 595b = 95585 }}}
Multiply both sides of (1) by {{{ 465 }}}
and subtract (1) from (2)
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(2) {{{ 465a + 595b = 95585 }}}
(1) {{{ -465a - 465b = -83235 }}}
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{{{ 130b = 12350 }}}
{{{ b = 95 }}}
and
(1) {{{ a + b = 179 }}}
(1) {{{ a + 95 = 179 }}}
(1) {{{ a = 84 }}}
He used 84 pounds of type A coffee
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check:
(2) {{{ 4.65*84 + 5.95*95 = 955.85 }}}
(2) {{{ 390.6 + 565.25 = 955.85 }}}
(2) {{{ 955.85 = 955.85 }}}
OK