Question 909126
Let {{{ k }}} = cost of a keyboard
Let {{{ m }}} = the cost of a monitor
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(1) {{{ 21k + 33m = 35564.25 }}}
(2) {{{ 41k + 36m = 49503.08 }}}
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Divide both sides of (1) by {{{ 11 }}}
Divide both sides of (2) by {{{ 12 }}}
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(1) {{{ (21k)/11 + 3m = 35564.25/11 }}}
(2) {{{ (41k)/12 + 3m = 49503.08/12 }}}
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Subtract (1) from (2)
(2) {{{ (41k)/12 + 3m = 49503.08/12 }}}
(1) {{{ -(21k)/11 - 3m = -35564.25/11 }}}
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{{{ ( 41k )/12  - ( 21k )/11 = 49503.08/12 - 35564.25/11 }}}
Multiply both sides by {{{ 12*11 }}}
{{{ 11*41k - 12*21k = 11*49503.08 - 12*35564.25 }}}
{{{ 451k - 252k = 544533.88 - 426771 }}}
{{{ 199k = 117762.88 }}}
{{{ k = 591.77326 }}}
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Plug this back into either equation to find {{{ m }}}
check my math, too