document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1169107>Question 1169107</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Dogs between 2 to 13 years old, age at an average rate of 4 human years for every dog year. The equation  describes the relationship between the dogs age x in dog-years and the dogs age in human-years y.\r<BR>\n" );
document.write( "\n" );
document.write( "a) Write the equation in y = mx +b form\r<BR>\n" );
document.write( "\n" );
document.write( "b)What is the age in human-years of a 7 year old dog?\r<BR>\n" );
document.write( "\n" );
document.write( "c) A friend tells you their dog is as old as their 60 year old grandparents. How old is the dog in dog-years? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #851441 by </B><A HREF=/tutors/aboutme.mpl?userid=MathLover1><B>MathLover1(20849)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=MathLover1><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=MathLover1><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=851441\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Dogs between <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2 ALIGN=MIDDLE  ALT=\"2\"   DISABLED_style= \"max-width:90%; height:auto;\" > to <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=13 ALIGN=MIDDLE  ALT=\"13\"   DISABLED_style= \"max-width:90%; height:auto;\" > years old, age at an average rate of <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=4 ALIGN=MIDDLE  ALT=\"4\"   DISABLED_style= \"max-width:90%; height:auto;\" > human years for every dog year. \r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "a)\r<BR>\n" );
document.write( "\n" );
document.write( "Write the equation in <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y+=+mx+%2Bb ALIGN=MIDDLE  ALT=\"y+=+mx+%2Bb\"   DISABLED_style= \"max-width:90%; height:auto;\" > form\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=mx+%2B+b+ ALIGN=MIDDLE  ALT=\"y=mx+%2B+b+\"   DISABLED_style= \"max-width:90%; height:auto;\" > where the dogs age is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x ALIGN=MIDDLE  ALT=\"x\"   DISABLED_style= \"max-width:90%; height:auto;\" >, and  the dogs age in human-years is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y ALIGN=MIDDLE  ALT=\"y\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "if given that <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=2 ALIGN=MIDDLE  ALT=\"x=2\"   DISABLED_style= \"max-width:90%; height:auto;\" >, then <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=2%2A4=8 ALIGN=MIDDLE  ALT=\"y=2%2A4=8\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=8=m%2A2+%2B+b+ ALIGN=MIDDLE  ALT=\"8=m%2A2+%2B+b+\"   DISABLED_style= \"max-width:90%; height:auto;\" > ......eq.1\r<BR>\n" );
document.write( "\n" );
document.write( "if given that <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=13 ALIGN=MIDDLE  ALT=\"x=13\"   DISABLED_style= \"max-width:90%; height:auto;\" >, then <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=13%2A4=52 ALIGN=MIDDLE  ALT=\"y=13%2A4=52\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=52=m%2A13+%2B+b+ ALIGN=MIDDLE  ALT=\"52=m%2A13+%2B+b+\"   DISABLED_style= \"max-width:90%; height:auto;\" > ......eq.2\r<BR>\n" );
document.write( "\n" );
document.write( "solve this system:\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=8=2m+%2B+b+ ALIGN=MIDDLE  ALT=\"8=2m+%2B+b+\"   DISABLED_style= \"max-width:90%; height:auto;\" > ......eq.1\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=52=13m+%2B+b+ ALIGN=MIDDLE  ALT=\"52=13m+%2B+b+\"   DISABLED_style= \"max-width:90%; height:auto;\" > ......eq.2<BR>\n" );
document.write( "_____________________________________ subtract eq.1 from eq.2\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=52-8=13m-2m+%2B+b-b+ ALIGN=MIDDLE  ALT=\"52-8=13m-2m+%2B+b-b+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=44=11m+ ALIGN=MIDDLE  ALT=\"44=11m+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=m=44%2F11+ ALIGN=MIDDLE  ALT=\"m=44%2F11+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=m=4+ ALIGN=MIDDLE  ALT=\"m=4+\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "substitute in eq.1 to calculate b\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=8=2%2A4+%2B+b+ ALIGN=MIDDLE  ALT=\"8=2%2A4+%2B+b+\"   DISABLED_style= \"max-width:90%; height:auto;\" > ......eq.1<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=8=8+%2B+b+ ALIGN=MIDDLE  ALT=\"8=8+%2B+b+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=8-8+=+b+ ALIGN=MIDDLE  ALT=\"8-8+=+b+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b=0+ ALIGN=MIDDLE  ALT=\"+b=0+\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "your equation is\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=4x++ ALIGN=MIDDLE  ALT=\"y=4x++\"   DISABLED_style= \"max-width:90%; height:auto;\" > \r<BR>\n" );
document.write( "\n" );
document.write( "b)\r<BR>\n" );
document.write( "\n" );
document.write( "What is the age in human-years of a <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=7+ ALIGN=MIDDLE  ALT=\"7+\"   DISABLED_style= \"max-width:90%; height:auto;\" >year old dog?\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=7 ALIGN=MIDDLE  ALT=\"x=7\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=4%2A7++ ALIGN=MIDDLE  ALT=\"y=4%2A7++\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=28++ ALIGN=MIDDLE  ALT=\"y=28++\"   DISABLED_style= \"max-width:90%; height:auto;\" > ->the age in human-years \r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "c)\r<BR>\n" );
document.write( "\n" );
document.write( "A friend tells you their dog is as old as their <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=60 ALIGN=MIDDLE  ALT=\"60\"   DISABLED_style= \"max-width:90%; height:auto;\" > year old grandparents. How old is the dog in dog-years?\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=60 ALIGN=MIDDLE  ALT=\"y=60\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=60=4x+ ALIGN=MIDDLE  ALT=\"60=4x+\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=60%2F4=x+ ALIGN=MIDDLE  ALT=\"60%2F4=x+\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=15+ ALIGN=MIDDLE  ALT=\"x=15+\"   DISABLED_style= \"max-width:90%; height:auto;\" >->  their dog is old <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=15 ALIGN=MIDDLE  ALT=\"15\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );