document.write( "Question 110439: I need your help with this problem: Determine a relationship between the x and y values. Write an equation. If X is 1,2,3,4. And Y is -6,-5,-4,and -3. If you do reply to me I greatly appriciate it for I have a test tomorro and I don't understand this question. I hope I wrote the question to where you can understand it easily. Thanks again for all your help! \n" ); document.write( "
Algebra.Com's Answer #80475 by edjones(8007)\"\" \"About 
You can put this solution on YOUR website!
(1,-6)(4,-3)
\n" ); document.write( "\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
Solved by pluggable solver: Finding the Equation of a Line
First lets find the slope through the points (\"1\",\"-6\") and (\"4\",\"-3\")
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"m=%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29\" Start with the slope formula (note: (\"x%5B1%5D\",\"y%5B1%5D\") is the first point (\"1\",\"-6\") and (\"x%5B2%5D\",\"y%5B2%5D\") is the second point (\"4\",\"-3\"))
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"m=%28-3--6%29%2F%284-1%29\" Plug in \"y%5B2%5D=-3\",\"y%5B1%5D=-6\",\"x%5B2%5D=4\",\"x%5B1%5D=1\" (these are the coordinates of given points)
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"m=+3%2F3\" Subtract the terms in the numerator \"-3--6\" to get \"3\". Subtract the terms in the denominator \"4-1\" to get \"3\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"m=1\" Reduce
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So the slope is
\n" ); document.write( "
\n" ); document.write( " \"m=1\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " ------------------------------------------------
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "Now let's use the point-slope formula to find the equation of the line:
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " ------Point-Slope Formula------
\n" ); document.write( " \"y-y%5B1%5D=m%28x-x%5B1%5D%29\" where \"m\" is the slope, and (\"x%5B1%5D\",\"y%5B1%5D\") is one of the given points
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So lets use the Point-Slope Formula to find the equation of the line
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"y--6=%281%29%28x-1%29\" Plug in \"m=1\", \"x%5B1%5D=1\", and \"y%5B1%5D=-6\" (these values are given)
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"y%2B6=%281%29%28x-1%29\" Rewrite \"y--6\" as \"y%2B6\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"y%2B6=1x%2B%281%29%28-1%29\" Distribute \"1\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"y%2B6=1x-1\" Multiply \"1\" and \"-1\" to get \"-1%2F1\". Now reduce \"-1%2F1\" to get \"-1\"
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( " \"y=1x-1-6\" Subtract \"6\" from both sides to isolate y
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"y=1x-7\" Combine like terms \"-1\" and \"-6\" to get \"-7\"
\n" ); document.write( "
\n" ); document.write( " ------------------------------------------------------------------------------------------------------------
\n" ); document.write( "
\n" ); document.write( " Answer:
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So the equation of the line which goes through the points (\"1\",\"-6\") and (\"4\",\"-3\") is:\"y=1x-7\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " The equation is now in \"y=mx%2Bb\" form (which is slope-intercept form) where the slope is \"m=1\" and the y-intercept is \"b=-7\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " Notice if we graph the equation \"y=1x-7\" and plot the points (\"1\",\"-6\") and (\"4\",\"-3\"), we get this: (note: if you need help with graphing, check out this solver)
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " Graph of \"y=1x-7\" through the points (\"1\",\"-6\") and (\"4\",\"-3\")
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " Notice how the two points lie on the line. This graphically verifies our answer.
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "

\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );