document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=73352>Question 73352</A>: <I><SPAN STYLE=\"word-break: break-all;\"> the fuel tank in a car was 40% full. i added 28 litres and then found it was 75% full. how much fuel does the tank hold?<BR>\n" );
document.write( "instructions: form equations to solve this worded problem </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #52512 by </B><A HREF=/tutors/aboutme.mpl?userid=bucky><B>bucky(2189)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=bucky><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=52512\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let x be the amount of gas the tank holds when full.  Then all you need to do is write the <BR>\n" );
document.write( "equation for the situation before you started.  That situation was that the tank was 40% (decimal 0.4) <BR>\n" );
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document.write( "So before you started you had 0.4*x litres in the tank representing 40% of a full tank.<BR>\n" );
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document.write( "Next you added 28 litres to that amount giving you what you started with plus 28 litres.<BR>\n" );
document.write( "So now the tank has in it:<BR>\n" );
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document.write( "0.4*x + 28<BR>\n" );
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document.write( "But you then find that this amount is 75% (decimal 0.75) of a full tank.  This can be written<BR>\n" );
document.write( "as 0.75*x.<BR>\n" );
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document.write( "Set the two equal to get:<BR>\n" );
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document.write( "0.4x + 28 = 0.75*x <BR>\n" );
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document.write( "Subtract 28 litres from both sides to eliminate the 28 litres from the left side and get:<BR>\n" );
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document.write( "0.4*x = 0.75x - 28<BR>\n" );
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document.write( "Now subtract 0.75*x from both sides to eliminate the 0.75*x from the right side. This subtraction<BR>\n" );
document.write( "results in:<BR>\n" );
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document.write( "-0.35*x = -28<BR>\n" );
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document.write( "Now just divide both sides by -0.35 and you find that:<BR>\n" );
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document.write( "x = -28/-0.35 = 80 litres<BR>\n" );
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document.write( "When the tank is full it contains 80 litres.<BR>\n" );
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document.write( "When you started the tank had 40% of 80 litres or it had 32 litres.  You added 28 litres<BR>\n" );
document.write( "and then the tank had 60 litres in it (32 plus 28).  And this 60 litres was 75% or 3/4 of <BR>\n" );
document.write( "a full tank.  All the figures check, so it looks as if our answer is correct.<BR>\n" );
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document.write( "Hope this helps you to understand the problem a little better. </SPAN>\n" );
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