document.write( "Question 230577: Hi. I was wondering if you could help me with this problem.\r
\n" ); document.write( "\n" ); document.write( "Given that f(3)=12 and f(5)=-2 find f(1/7)\r
\n" ); document.write( "\n" ); document.write( "I've tried the f(x)=mx+b formula\r
\n" ); document.write( "\n" ); document.write( "f(3)=m(3)+b=12
\n" ); document.write( "f(5)=m(5)+b=-2\r
\n" ); document.write( "\n" ); document.write( "5-3=2m and -2-12=-14\r
\n" ); document.write( "\n" ); document.write( "M=-14/-2
\n" ); document.write( "M=-7\r
\n" ); document.write( "\n" ); document.write( "And this is where I get stuck. \r
\n" ); document.write( "\n" ); document.write( "Thank you \n" ); document.write( "
Algebra.Com's Answer #170736 by jsmallt9(3758)\"\" \"About 
You can put this solution on YOUR website!
>Given that f(3)=12 and f(5)=-2 find f(1/7)\r
\n" ); document.write( "\n" ); document.write( ">I've tried the f(x)=mx+b formula
\n" ); document.write( "Good idea.\r
\n" ); document.write( "\n" ); document.write( ">f(3)=m(3)+b=12
\n" ); document.write( ">f(5)=m(5)+b=-2
\n" ); document.write( "The way you've written this is confusing. It would be better as:
\n" ); document.write( "12 = m(3) + b
\n" ); document.write( "-2 = m(5) + b\r
\n" ); document.write( "\n" ); document.write( ">M=-14/-2
\n" ); document.write( ">M=-7
\n" ); document.write( "Still good.

\n" ); document.write( "Now we just use this value for \"m\" to find \"b\". We can substitute into either equation:
\n" ); document.write( "12 = (-7)(3) + b
\n" ); document.write( "12 = -21 + b
\n" ); document.write( "33 = b

\n" ); document.write( "So the function is:
\n" ); document.write( "f(x) = -7x + 33

\n" ); document.write( "And finally we can use this to find f(1/7):
\n" ); document.write( "f(1/7) = -7(1/7) + 33
\n" ); document.write( "f(1/7) = -1 + 33
\n" ); document.write( "f(1/7) = 32
\n" ); document.write( " \n" ); document.write( "
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