document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1181280>Question 1181280</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The first four terms of an arithmetic sequence are 2, a-b, 2a+b+7, a-3b . Find a and b. <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 #811178 by </B><A HREF=/tutors/aboutme.mpl?userid=ikleyn><B>ikleyn(53756)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ikleyn><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=ikleyn><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=811178\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> .\r<BR>\n" );
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document.write( "In this problem, there are two unknowns, &nbsp;\"a\" &nbsp;and &nbsp;\"b\";  \r<BR>\n" );
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document.write( "so, &nbsp;you need to construct two equations for these two unknowns.\r<BR>\n" );
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document.write( "There is the &nbsp;STANDARD &nbsp;WAY &nbsp;to construct these two equations:\r<BR>\n" );
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document.write( "<PRE STYLE=\"white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;\">\r\n" );
document.write( "    first  equation says that  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a%5B2%5D-a%5B1%5D ALIGN=MIDDLE  ALT=\"a%5B2%5D-a%5B1%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a%5B3%5D-a%5B2%5D ALIGN=MIDDLE  ALT=\"a%5B3%5D-a%5B2%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" >  (both sides represent the common difference)\r\n" );
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document.write( "    second equation says that  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a%5B3%5D-a%5B2%5D ALIGN=MIDDLE  ALT=\"a%5B3%5D-a%5B2%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a%5B4%5D-a%5B3%5D ALIGN=MIDDLE  ALT=\"a%5B4%5D-a%5B3%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" >  (both sides represent the common difference, again).\r\n" );
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document.write( "It is the way on how @MathTherapy solves the problem in his post.\r<BR>\n" );
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document.write( "How @Mathlover1 and @josgarithmetic do it, &nbsp;it looks like chewing gum in the mouth <BR>\n" );
document.write( "instead of solving problem and instead of right teaching . . . \r<BR>\n" );
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document.write( "You, &nbsp;probably, &nbsp;will solve tens of such problems in your life &nbsp;(in your school years).\r<BR>\n" );
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document.write( "THEREFORE, &nbsp;you need to know the right way and do not spend your time for nothing . . . \r<BR>\n" );
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document.write( "To see many other similar &nbsp;(and different) &nbsp;problems solved, &nbsp;look into the lessons\r<BR>\n" );
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document.write( "&nbsp;&nbsp;&nbsp;&nbsp;- <A  rel=nofollow HREF=http://www.algebra.com/algebra/homework/Sequences-and-series/One-characteristic-property-of-arithmetic-progressions.lesson>One characteristic property of arithmetic progressions</A>\r<BR>\n" );
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document.write( "&nbsp;&nbsp;&nbsp;&nbsp;- <A  rel=nofollow HREF=https://www.algebra.com/algebra/homework/Sequences-and-series/Finding-number-of-terms-of-an-arithmeti--progression.lesson>Finding number of terms of an arithmetic progression</A> \r<BR>\n" );
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document.write( "&nbsp;&nbsp;&nbsp;&nbsp;- <A  rel=nofollow HREF=https://www.algebra.com/algebra/homework/Sequences-and-series/Inserting-arithmetic-means-between-given-numbers.lesson>Inserting arithmetic means between given numbers</A> \r<BR>\n" );
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document.write( "in this site.\r<BR>\n" );
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document.write( "Also, &nbsp;you have this free of charge online textbook in &nbsp;ALGEBRA-II &nbsp;in this site\r<BR>\n" );
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document.write( "&nbsp;&nbsp;&nbsp;&nbsp;- <A  rel=nofollow HREF=https://www.algebra.com/algebra/homework/complex/ALGEBRA-II-YOUR-ONLINE-TEXTBOOK.lesson>ALGEBRA-II - YOUR ONLINE TEXTBOOK</A>.\r<BR>\n" );
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document.write( "The referred lessons are the part of this online textbook under the topic <BR>\n" );
document.write( "<U>\"Arithmetic progressions\"</U>.\r<BR>\n" );
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