SOLUTION: Hi sam could buy 4 magazine s and 3 books with all his money. He decided to buy 2 magazine s and a book. He then had 84 dollars left. If a magazine cost 1/3 the price of a book ,

Algebra ->  Customizable Word Problem Solvers  -> Misc -> SOLUTION: Hi sam could buy 4 magazine s and 3 books with all his money. He decided to buy 2 magazine s and a book. He then had 84 dollars left. If a magazine cost 1/3 the price of a book ,       Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 1047202: Hi
sam could buy 4 magazine s and 3 books with all his money. He decided to buy 2 magazine s and a book. He then had 84 dollars left. If a magazine cost 1/3 the price of a book , how much did sam have in the beginning.
thanks
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
The +A+ = amount he had in the beginning
+m+ = the cost of a magazine
+b+ = the cost of a book
---------------------------
(1) +A+=+4m+%2B+3b+
(2) +A+=+2m+%2B+b+%2B+84+
(3) +m+=+%281%2F3%29%2Ab+
------------------------
(3) +b+=+3m+
and
(1) +A+=+4m+%2B+3%2A%283m%29+
(1) +A+=+13m+
and
(2) +A+=+2m+%2B+3m+%2B+84+
(2) +A+=+5m+%2B+84+
Plug (1) into (2)
(2) +13m+=+5m+%2B+84+
(2) +8m+=+84+
(2) +m+=+10.5+
and
(3) +b+=+3m+
(3) +b+=+3%2A10.5+
(3) +b+=+31.5+
--------------------
(1) +A+=+4m+%2B+3b+
(1) +A+=+4%2A10.5+%2B+3%2A31.5+
(1) +A+=+42+%2B+94.5+
(1) +A+=+136.5+
He started with $136.50
-----------------------
check:
(2) +A+=+2m+%2B+b+%2B+84+
(2) +A+=+2%2A10.5+%2B+31.5+%2B+84+
(2) +A+=+21+%2B+115.5+
(2) +A+=+136.5+
OK