document.write( "Question 936847: If f(4)=0 and f(6)=6. Which of the following couldd represent f(x)? Answer is 2/3x-4. How? \n" ); document.write( "

Algebra.Com's Answer #570331 by Fombitz(32388) $\"\"$ $\"About$

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The line has the form, $\"y=mx%2Bb\"$
\n" ); document.write( "Use the two points to find m and b.
\n" ); document.write( " $\"0=m%284%29%2Bb\"$
\n" ); document.write( " $\"4m%2Bb=0\"$
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\n" ); document.write( " $\"6=m%286%29%2Bb\"$
\n" ); document.write( " $\"6m%2Bb=6\"$
\n" ); document.write( "Subtract the first equation from the second to eliminate b.
\n" ); document.write( " $\"6m%2Bb-4m-b=6-0\"$
\n" ); document.write( " $\"2m=6\"$
\n" ); document.write( " $\"m=3\"$
\n" ); document.write( "Then use either equation to solve for b.
\n" ); document.write( " $\"4%283%29%2Bb=0\"$
\n" ); document.write( " $\"12%2Bb=0\"$
\n" ); document.write( " $\"b=-12\"$
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\n" ); document.write( " $\"highlight%28y=3x-12%29\"$
\n" ); document.write( "Checking the solution,
\n" ); document.write( " $\"3%284%29-12=0\"$
\n" ); document.write( " $\"3%286%29-12=6\"$
\n" ); document.write( "Both points have been verified.
\n" ); document.write( " $\"y=%282%2F3%29x-4\"$ is not the correct solution to this problem.
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