document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=155468>Question 155468</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I don't understand how to set up this problem nor solve it?\r<BR>\n" );
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document.write( "In a family there are two cars.  In a given week,the first car gets an average of 25 miles per gallon, and the second car gets 40 miles per gallon. The two cars combined drives a total of 1825 miles in that one week, for a total gas consumption of 55 gallons. How many gallons were consumed by each of the two cars that week? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #114497 by </B><A HREF=/tutors/aboutme.mpl?userid=nerdybill><B>nerdybill(7384)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=nerdybill><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/cgi-bin/show-face.mpl?user=nerdybill><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=114497\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> In a family there are two cars. In a given week,the first car gets an average of 25 miles per gallon, and the second car gets 40 miles per gallon. The two cars combined drives a total of 1825 miles in that one week, for a total gas consumption of 55 gallons. How many gallons were consumed by each of the two cars that week?<BR>\n" );
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document.write( "Let x = amt of gas consumed by first car<BR>\n" );
document.write( "and y = amt of gas consumed by second car<BR>\n" );
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document.write( "25x + 40y = 1825 (equation 1)<BR>\n" );
document.write( "  x +   y = 55   (equation 2)<BR>\n" );
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document.write( "solve equation 2 for y:<BR>\n" );
document.write( "x+y = 55<BR>\n" );
document.write( "y = 55-x<BR>\n" );
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document.write( "Use the above, and substitute it into equation 1 and solve for x:<BR>\n" );
document.write( "25x + 40y = 1825<BR>\n" );
document.write( "25x + 40(55-x) = 1825<BR>\n" );
document.write( "25x + 2200 - 40x = 1825<BR>\n" );
document.write( "2200 - 15x = 1825<BR>\n" );
document.write( "- 15x = -375<BR>\n" );
document.write( "x = -375/-15<BR>\n" );
document.write( "x = 25 gallons (gas consumed by 25 mpg car)<BR>\n" );
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document.write( "From equation 2:<BR>\n" );
document.write( "  x +   y = 55<BR>\n" );
document.write( "  25 +   y = 55<BR>\n" );
document.write( "y = 55-25<BR>\n" );
document.write( "y = 30 gallons (gas consumed by 40 mpg car) </SPAN>\n" );
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