document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=114144>Question 114144</A>: <I><SPAN STYLE=\"word-break: break-all;\"> please help me with this problem, i try to solve it by studying your examples, but i really can't get it right...here's the problem:\r<BR>\n" );
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document.write( "PERLA IS NOW 5 TIMES AS OLD AS MARILOU.  IN 10 YEARS, PERLA WILL BE 3 TIMES AS OLD AS MARILOU.  HOW OLD IS EACH?  Kindly solve and show the solution.  Below is my attempt to solve it.  But I guess, its wrong.\r<BR>\n" );
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document.write( "Here's my attempt:\r<BR>\n" );
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document.write( "let P be Perla's age  and M be Marilou's age\r<BR>\n" );
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document.write( "a) P = 5M<BR>\n" );
document.write( "b) P+10 = 3M<BR>\n" );
document.write( "then substirute all the Ps to Ms\r<BR>\n" );
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document.write( "b) P + 10 = 3M<BR>\n" );
document.write( "  5M +10 = 3M<BR>\n" );
document.write( "  5M - 3M = -10\r<BR>\n" );
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document.write( "this is how far as i've gone...it seems that this is wrong since there is a negative number.. Please help me.  Thank you. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #83068 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=83068\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Here's your work. You had a very good start on the problem:<BR>\n" );
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document.write( "let P be Perla's age  and M be Marilou's age <=== good. Your selection of P for Perla's age <BR>\n" );
document.write( "and M for Marilou's age helps you to identify the ages better than X and Y or some other letters.\r<BR>\n" );
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document.write( "a) P = 5M <=== this is correct<BR>\n" );
document.write( "b) P+10 = 3M <=== your mistake is here.<BR>\n" );
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document.write( "In 10 years, Perla's age will be P + 10, just as you showed on the left side. But Marilou<BR>\n" );
document.write( "will have aged 10 years also, so her age at that time will be M + 10. So three times her age<BR>\n" );
document.write( "at that time would make the equation become:<BR>\n" );
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document.write( "P + 10 = 3(M + 10)<BR>\n" );
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document.write( "and you can simplify this by multiplying out the right side to get:<BR>\n" );
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document.write( "P + 10 = 3M + 30<BR>\n" );
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document.write( "Get rid of the 10 on the right side by subtracting 10 from both sides to get:<BR>\n" );
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document.write( "P = 3M + 20<BR>\n" );
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document.write( "But up in step a) you found that P = 5M. So you can substitute 5M for P and the equation is:<BR>\n" );
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document.write( "5M = 3M + 20<BR>\n" );
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document.write( "Get rid of the 3M on the right side by subtracting 3M from both sides. This makes the<BR>\n" );
document.write( "equation reduce to:<BR>\n" );
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document.write( "2M = 20<BR>\n" );
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document.write( "and solve for M (which is Marilou's present age) by dividing both sides by 2 to get:<BR>\n" );
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document.write( "M = 10<BR>\n" );
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document.write( "So Marilou is presently 10 years old. <BR>\n" );
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document.write( "and since Perla is 5 times older than Marilou, Perla is 5*10 or 50 years old.<BR>\n" );
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document.write( "Ten years from now Perla will be 60 years old. And 10 years from now Marilou will be<BR>\n" );
document.write( "20 years old. And sure enough, in 10 years Perla's age (60) will be three times Marilou's <BR>\n" );
document.write( "age (20). So this answer checks.<BR>\n" );
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document.write( "Your thinking was right on ... you just made a very common error ... you forgot that Marilou's <BR>\n" );
document.write( "age went up by 10 years also. That's an easy mistake to make, but now you should have the idea.<BR>\n" );
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document.write( "Keep up the good work ... you've got the basic idea of how to do these problems and with<BR>\n" );
document.write( "a little practice you'll be good at it.<BR>\n" );
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document.write( "Hope this helps.<BR>\n" );
document.write( ". </SPAN>\n" );
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