document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=244886>Question 244886</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A box containing 40 nails weighs 175 grams. The same box with 20 nails weighs 95 grams. What is the sum of the weight of the box and one nail?\r<BR>\n" );
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document.write( "(A) 4 (B) 9.5 (C) 15 (D) 19 (E) 69.7 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #179033 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=179033\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> we have the weight of the box which is represented by b.\r<BR>\n" );
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document.write( "we have the weight of the nails which is represented by n.\r<BR>\n" );
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document.write( "first formula is:\r<BR>\n" );
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document.write( "b + 40*n = 175\r<BR>\n" );
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document.write( "second formula is:\r<BR>\n" );
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document.write( "b + 20*n = 95\r<BR>\n" );
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document.write( "in both equations, solve for b.\r<BR>\n" );
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document.write( "b + 40*n = 175 becomes b = 175 - 40*n\r<BR>\n" );
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document.write( "b + 20*n = 95 becomes b = 95 - 20*n\r<BR>\n" );
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document.write( "since they both equal to b, then they are equal to each other so we get:\r<BR>\n" );
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document.write( "175 - 40*n = 95 - 20*n\r<BR>\n" );
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document.write( "add 40*n to both sides of this equation and subtract 95 from both sides of this equation to get:\r<BR>\n" );
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document.write( "175 - 95 = -20*n + 40*n\r<BR>\n" );
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document.write( "combine like terms to get:\r<BR>\n" );
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document.write( "80 = 20*n\r<BR>\n" );
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document.write( "divide both sides of this equation by 20 to get:\r<BR>\n" );
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document.write( "n = 4 grams\r<BR>\n" );
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document.write( "substitute in your first equation of b + 40*n = 175 to get:\r<BR>\n" );
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document.write( "b + 40*4 = 175\r<BR>\n" );
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document.write( "subtract 40*4 from both sides of equation and simplify to get:\r<BR>\n" );
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document.write( "b = 175 - 160\r<BR>\n" );
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document.write( "simplify further to get:\r<BR>\n" );
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document.write( "b = 15\r<BR>\n" );
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document.write( "use the value of b  = 15 and n = 4 in the second equation to get:\r<BR>\n" );
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document.write( "b + 20*n = 95 becomes:\r<BR>\n" );
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document.write( "15 + 20*4 = 95 becomes:\r<BR>\n" );
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document.write( "15 + 80 = 95 which is true so the values for b and n are good.\r<BR>\n" );
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document.write( "You have:\r<BR>\n" );
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document.write( "b = 15<BR>\n" );
document.write( "n = 4\r<BR>\n" );
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document.write( "b + n = 19\r<BR>\n" );
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document.write( "Answer to your question is:\r<BR>\n" );
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document.write( "the box and one nail weigh 19 grams which is selection D.\r<BR>\n" );
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