document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1200411>Question 1200411</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I subtrated 8 from a certain number. I then multiply the result by3. The final ananswer is 21.find the original number </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #834534 by </B><A HREF=/tutors/aboutme.mpl?userid=math_tutor2020><B>math_tutor2020(3817)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=math_tutor2020><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=834534\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <font color=black size=3><BR>\n" );
document.write( "x = starting unknown number<BR>\n" );
document.write( "x-8 = subtract off 8<BR>\n" );
document.write( "3(x-8) = multiply the result by 3<BR>\n" );
document.write( "<font color=blue>3(x-8) = 21</font> is the equation to set up\r<BR>\n" );
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document.write( "Let's isolate x. <BR>\n" );
document.write( "To do so, we follow PEMDAS in reverse to undo what happens to x.<BR>\n" );
document.write( "The last thing that happened was \"multiply by 3\", which means we undo that by dividing both sides by 3<BR>\n" );
document.write( "3(x-8) = 21<BR>\n" );
document.write( "3(x-8)/3 = 21/3<BR>\n" );
document.write( "x-8 = 7\r<BR>\n" );
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document.write( "Then we add 8 to both sides to undo the \"minus 8\" aka \"subtract 8\".<BR>\n" );
document.write( "x-8 = 7<BR>\n" );
document.write( "x-8+8 = 7+8<BR>\n" );
document.write( "x = 15\r<BR>\n" );
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document.write( "Here are all of the steps in one big block<BR>\n" );
document.write( "3(x-8) = 21<BR>\n" );
document.write( "3(x-8)/3 = 21/3<BR>\n" );
document.write( "x-8 = 7<BR>\n" );
document.write( "x-8+8 = 7+8<BR>\n" );
document.write( "x = 15\r<BR>\n" );
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document.write( "Here is another route we could take through the use of the distributive property<BR>\n" );
document.write( "3(x-8) = 21<BR>\n" );
document.write( "3x-24 = 21<BR>\n" );
document.write( "3x-24+24 = 21+24<BR>\n" );
document.write( "3x = 45<BR>\n" );
document.write( "3x/3 = 45/3<BR>\n" );
document.write( "x = 15\r<BR>\n" );
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document.write( "Check:<BR>\n" );
document.write( "Starting number = 15<BR>\n" );
document.write( "Subtract off 8 to get 15-8 = 7<BR>\n" );
document.write( "Triple the result: 7*3 = 21<BR>\n" );
document.write( "The answer is confirmed.\r<BR>\n" );
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document.write( "Answer: <font color=red>15</font><BR>\n" );
document.write( "</font> </SPAN>\n" );
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