document.write( "Question 1142546: hello i have been working on this question for a while but I keep getting so confuse with what i have been writing on my piece of paper.\r
\n" ); document.write( "\n" ); document.write( "Kyle works at a donut factory, where a 10-oz cup of coffee costs 95cents, a 14-oz cup costs $1.15, and a 20-oz cup costs $1.50. During one busy period, Kyle served 31 cups of coffee, using 484 ounces of coffee, while collecting a total of $38.80. How many cups of each size did Kyle fill? \n" ); document.write( "

Algebra.Com's Answer #763239 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+a+\"$ = number of 10-oz cups filled
\n" ); document.write( "Let $\"+b+\"$ = number of 14-oz cups filled
\n" ); document.write( "Let $\"+c+\"$ = number of 20-oz cups filled
\n" ); document.write( "------------------------------------------------
\n" ); document.write( "(1) $\"+a+%2B+b+%2B+c+=+31+\"$
\n" ); document.write( "(2) $\"+10a+%2B+14b+%2B+20c+=+484+\"$
\n" ); document.write( "(3) $\"+95a+%2B+115b+%2B+150c+=+3880+\"$ ( in cents )
\n" ); document.write( "-----------------------------------------------------
\n" ); document.write( "There are 3 equations with 3 unknowns, so it's solvable.
\n" ); document.write( "(2) $\"+5a+%2B+7b+%2B+10c+=+242+\"$
\n" ); document.write( "and
\n" ); document.write( "(3) $\"+19a+%2B+23b+%2B+30c+=+776+\"$
\n" ); document.write( "and
\n" ); document.write( "(1) $\"+7a+%2B+7b+%2B+7c+=+210+\"$
\n" ); document.write( "---------------------------------------
\n" ); document.write( "Subtract (1) from (2)
\n" ); document.write( "(2) $\"+5a+%2B+7b+%2B+10c+=+242+\"$
\n" ); document.write( "(1) $\"+-7a+-+7b+-+7c+=+-210+\"$
\n" ); document.write( "-----------------------------------
\n" ); document.write( " $\"+-2a+%2B+3c+=+32+\"$
\n" ); document.write( " $\"+-20a+%2B+30c+=+320+\"$
\n" ); document.write( "Subtract this from (3)
\n" ); document.write( "(3) $\"+19a+%2B+23b+%2B+30c+=+776+\"$
\n" ); document.write( " $\"+20a+++++++++++++-30c+=+-320+\"$
\n" ); document.write( "-------------------------------------
\n" ); document.write( " $\"+39a+%2B+23b+=+456+\"$
\n" ); document.write( " $\"+-23a+-+23b+-23c+=+-713+\"$
\n" ); document.write( "-----------------------------------
\n" ); document.write( " $\"+23c+-+16a+=+257+\"$
\n" ); document.write( " $\"+-24c+%2B+16a+=+-256+\"$
\n" ); document.write( "-----------------------------
\n" ); document.write( " $\"+-c+=+1+\"$
\n" ); document.write( "Looks like I switched a sign. You can
\n" ); document.write( "finish. Maybe $\"+c=1+\"$ ??\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

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