document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=2753>Question 2753</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I am studying for my 8th grade algebra final and i dont understand the way that on this linear system       4x+5y = 7     <BR>\n" );
document.write( "                         6x-2y = -18\r<BR>\n" );
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document.write( "how do i do this x = (7 -5y)/4\r<BR>\n" );
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document.write( "Substituting this expression into the second equation:\r<BR>\n" );
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document.write( "	6(7+5y)/4-2y = -18<BR>\n" );
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document.write( "and from after that  how do i simplify this 	6(7+5y)/4-2y = -18  \r<BR>\n" );
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document.write( "into this (-38)y = -114\r<BR>\n" );
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document.write( "I listen in class but i was absent on some very important days and this doesnt make sence\r<BR>\n" );
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document.write( "I thank anyone who could help.\r<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #1188 by </B><A HREF=/tutors/aboutme.mpl?userid=WannabeCAgirl83><B>WannabeCAgirl83(35)</B></A><img src=\"/images/stars/stars-07.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=WannabeCAgirl83><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=1188\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> You’re right. It doesn’t make sense that way because there are errors... ;-)\r<BR>\n" );
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document.write( "Your first aim is to bring x all alone on one side of the equation in order to find out what it equals, so that you can substitute x by its equivalent and thereby “get rid” of x as an unknown variable. Here’s how to do it:\r<BR>\n" );
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document.write( "4x + 5y = 7 | - 5y on both sides<BR>\n" );
document.write( "4x = 7 - 5y | / 4 on both sides<BR>\n" );
document.write( "x = 7/4 - 5/4y\r<BR>\n" );
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document.write( "As you found out that x is equal to 7/4 - 5/4y, you can substitute it in the next equation:\r<BR>\n" );
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document.write( "6x - 2y = -18 <BR>\n" );
document.write( "6(7/4 - 5/4y) - 2y = -18 \r<BR>\n" );
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document.write( "Thereby you “got rid” of x and are now only dealing with one unknown variable (y) instead of two (x and y).\r<BR>\n" );
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document.write( "Your second aim is now to “get rid” of y the same way you “got rid” of x: You have to bring y all alone on one side of the equation to find out what it equals. Here’s how:\r<BR>\n" );
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document.write( "6(7/4 - 5/4y) - 2y = -18 <BR>\n" );
document.write( "10 ˝ - 7 ˝y  - 2y = - 18<BR>\n" );
document.write( "10 ˝ - 9 ˝ y = - 18 | - 10 ˝<BR>\n" );
document.write( "- 9 ˝y = - 28 ˝ | / -9 ˝ <BR>\n" );
document.write( "y = 3\r<BR>\n" );
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document.write( "As you found out that y is equal to 3, you can substitute it in one of your equations in order to get a value for x:\r<BR>\n" );
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document.write( "4x + 5y = 7<BR>\n" );
document.write( "4x +5(3) = 7<BR>\n" );
document.write( "4x + 15 = 7 | - 15<BR>\n" );
document.write( "4x = -8 | / 4<BR>\n" );
document.write( "x = -2\r<BR>\n" );
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document.write( "Now you “got rid” of both of your unknown variables as you found out that:\r<BR>\n" );
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document.write( "x = -2  and  y = 3\r<BR>\n" );
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document.write( "Let’s check if the values for x and y are correct by putting them in the original equations:\r<BR>\n" );
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document.write( "4x + 5y = 7 <BR>\n" );
document.write( "4(-2) + 5(3) = 7  &#8594;  true\r<BR>\n" );
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document.write( "6x - 2y = - 18 <BR>\n" );
document.write( "6(-2)  - 2(3)  = - 18  &#8594;  true\r<BR>\n" );
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