document.write( "Question 158974This question is from textbook
\n" ); document.write( ": Trisha is on vacation. She sends letters and postcards to her friends at home. she needs 33 cents in postage for each letter and 20 cents for each postcard. she spends $3.58 in postage. how many letters and postcards did she send? \n" ); document.write( "
Algebra.Com's Answer #117244 by ankor@dixie-net.com(22740)\"\" \"About 
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She needs 33 cents in postage for each letter, and 20 cents for each postcard.
\n" ); document.write( "She spends $3.58 in postage. How many letters and postcards did she send?
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\n" ); document.write( "Let x = no. of letters
\n" ); document.write( "Let y = no. of postcards
\n" ); document.write( ":
\n" ); document.write( ".33x + .20y = 3.58
\n" ); document.write( ";
\n" ); document.write( ".2y = 3.58 - .33x
\n" ); document.write( ":
\n" ); document.write( "y = \"%283.58-.33x%29%2F.2\"
\n" ); document.write( "y = 17.9 - 1.65x
\n" ); document.write( ":
\n" ); document.write( "Substitute integers values for x, until you get an integer value for y
\n" ); document.write( ":
\n" ); document.write( "x = 6 will work
\n" ); document.write( "y = 17.9 - 1.65(6)
\n" ); document.write( "y = 17.9 - 9.9
\n" ); document.write( "y = 8
\n" ); document.write( ":
\n" ); document.write( "We have 6 letters, 8 post cards
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\n" ); document.write( ":
\n" ); document.write( "Check:
\n" ); document.write( " .33(6) + .20(8) =
\n" ); document.write( "1.98 + 1.60 = 3.58 \n" ); document.write( "
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