document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=980568>Question 980568</A>: <I><SPAN STYLE=\"word-break: break-all;\"> P(A or B) =1/4, P(A)=1/7, and P(AandB)=1/9, FindP(B)  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #601712 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><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=601712\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let x = P(B)\r<BR>\n" );
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document.write( "P(A or B) = P(A) + P(B) - P(A and B)\r<BR>\n" );
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document.write( "1/9 = 1/7 + x - 1/9\r<BR>\n" );
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document.write( "1/9 <font color=\"blue\">+ 1/9</font> = 1/7 + x - 1/9 <font color=\"blue\">+ 1/9</font> ... Add 1/9 to both sides\r<BR>\n" );
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document.write( "2/9 = 1/7 + x\r<BR>\n" );
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document.write( "x + 1/7 = 2/9\r<BR>\n" );
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document.write( "x + 1/7 <font color=\"blue\">- 1/7</font> = 2/9 <font color=\"blue\">- 1/7</font> ... Subtract 1/7 from both sides.\r<BR>\n" );
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document.write( "x = 2/9 - 1/7\r<BR>\n" );
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document.write( "x = 14/63 - 9/63\r<BR>\n" );
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document.write( "x = 5/63\r<BR>\n" );
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document.write( "So, P(B) = 5/63 </SPAN>\n" );
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