document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=78341>Question 78341</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Please help me with this problem I don't understand how to do this. Thank you.   Q:find the value of x.\r<BR>\n" );
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document.write( "30/48= 15/x+9 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #56185 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=56185\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Given:<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=30%2F48=+15%2F%28x%2B9%29 ALIGN=MIDDLE  ALT=\"30%2F48=+15%2F%28x%2B9%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "A simple rule that you can remember in working proportion problems is that you can begin to<BR>\n" );
document.write( "solve them by cross-multiplying and then setting the two products equal.<BR>\n" );
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document.write( "Multiply the numerator of the left side times the denominator of the right side.  Then<BR>\n" );
document.write( "multiply the denominator of the left side times the numerator of the right side.  Finally,<BR>\n" );
document.write( "set these two products equal.<BR>\n" );
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document.write( "[Note that you can imagine a line connecting the numerator on the left with the denominator<BR>\n" );
document.write( "on the right, and then imagine another line connecting the denominator on the left with<BR>\n" );
document.write( "the numerator on the right. These two lines cross ... and since each line connects<BR>\n" );
document.write( "the numbers to be multiplied they are referred to as cross products.]<BR>\n" );
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document.write( "Doing the cross products for this proportion and setting them equal results in:<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=30%28x%2B9%29+=+48%2A15 ALIGN=MIDDLE  ALT=\"30%28x%2B9%29+=+48%2A15\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "Doing the distributed multiplication of the left side gives:<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=30x+%2B+270+=+48%2A15 ALIGN=MIDDLE  ALT=\"30x+%2B+270+=+48%2A15\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "(the 270 comes from 30*9}.  Then multiply the right side 48*15 and the equation becomes:<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=30x+%2B+270+=+720 ALIGN=MIDDLE  ALT=\"30x+%2B+270+=+720\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "Now just solve like you would an equation.  Isolate the term on the left that contains<BR>\n" );
document.write( "the \"x\" by subtracting 270 from the left side.  But when you do that you have to also<BR>\n" );
document.write( "subtract 270 from the right side.  This process is:<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=30x+%2B+270+-+270+=+720+-+270 ALIGN=MIDDLE  ALT=\"30x+%2B+270+-+270+=+720+-+270\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "and doing the subtraction results in:<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=30x+=+450 ALIGN=MIDDLE  ALT=\"30x+=+450\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "Solve for x by dividing by 30, the multiplier of x to get:<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+450%2F30+=+15 ALIGN=MIDDLE  ALT=\"x+=+450%2F30+=+15\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "The answer to the problem is x = 15.  Check it by returning to the original problem and<BR>\n" );
document.write( "substituting 15 for x.  When you do that you get:<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=30%2F48=+15%2F%28x%2B9%29 ALIGN=MIDDLE  ALT=\"30%2F48=+15%2F%28x%2B9%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=30%2F48=+15%2F%2815%2B9%29 ALIGN=MIDDLE  ALT=\"30%2F48=+15%2F%2815%2B9%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "Add the terms in the parentheses and the equation becomes:<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=30%2F48=+15%2F24 ALIGN=MIDDLE  ALT=\"30%2F48=+15%2F24\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "Now divide 30 by 48 and see if you get the same answer as you do when you divide 15 by 24.<BR>\n" );
document.write( "You will, and this shows that when you use 15 for x, the equation will be true ... both<BR>\n" );
document.write( "sides will be equal.<BR>\n" );
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document.write( "Hope this helps to expand your knowledge of how to solve proportions ... (a proportion<BR>\n" );
document.write( "occurs when two ratios are set equal).<BR>\n" );
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