SOLUTION: Could you please help me with this problem? I have a hard time figuring out how to set up word problems... The Family Arts Center charges $21 for adults, $14 for Senior citizen

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Question 171693: Could you please help me with this problem? I have a hard time figuring out how to set up word problems...
The Family Arts Center charges $21 for adults, $14 for Senior citizens, and $5 for children under 12 for their live performances on Sunday afternoon. This past Sunday, the paid revenue was $9417 for 735 tickets sold. There were 43 more children than adults. How many children attended?
Thank you so much for your help...

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
What I do that really helps me is to
immediately assign letters for the
unknown quantities in the equation:
Let a= the number of adults attending
Let s= the number of Seniors attending
Let c= the number of children attending
--------------
Now I can write equations
(1) 735+=+a+%2B+s+%2B+c
(2) 9417+=+21a+%2B+14s+%2B+5c
(3) c+=+a+%2B+43
-------------
There are 3 equations and 3 unknowns, so it
should be solvable
Multiply (1) by 14 and subtract (2) from (1)
(1) 10290+=+14a+%2B+14s+%2B+14c
873+=+-7a+%2B+9c
Substitute (3)
873+=+-7a+%2B+9%2A%28a+%2B+43%29
873+=+-7a+%2B+9a+%2B+387
2a+=+486
a+=+243
Since (3) is given,
c+=+243+%2B+43
c+=+286
And, from (1)
735+=+243+%2B+s+%2B+286
s+=+206
286 children attended
check answer:
(2) 9417+=+21a+%2B+14s+%2B+5c
9417+=+21%2A243+%2B+14%2A206+%2B+5%2A286
9417+=+5103+%2B+2884+%2B+1430
9417+=+9417
(1) 735+=+a+%2B+s+%2B+c
735+=+243+%2B+206+%2B+286
735+=+735
(3) c+=+a+%2B+43
286+=+243+%2B+43
286+=+286
OK