document.write( "Question 111575: Please help\r
\n" ); document.write( "\n" ); document.write( "Write the equation of the line passing through each of the given pairs of points.\r
\n" ); document.write( "\n" ); document.write( "(-3, 3) and (4, -2)
\n" ); document.write( "Write your results in slope-intercept form, where possible.\r
\n" ); document.write( "\n" ); document.write( "Thanks
\n" ); document.write( "JMS
\n" ); document.write( "

Algebra.Com's Answer #81363 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
\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 (\"-3\",\"3\") and (\"4\",\"-2\")
\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 (\"-3\",\"3\") and (\"x%5B2%5D\",\"y%5B2%5D\") is the second point (\"4\",\"-2\"))
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"m=%28-2-3%29%2F%284--3%29\" Plug in \"y%5B2%5D=-2\",\"y%5B1%5D=3\",\"x%5B2%5D=4\",\"x%5B1%5D=-3\" (these are the coordinates of given points)
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"m=+-5%2F7\" Subtract the terms in the numerator \"-2-3\" to get \"-5\". Subtract the terms in the denominator \"4--3\" to get \"7\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So the slope is
\n" ); document.write( "
\n" ); document.write( " \"m=-5%2F7\"
\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-3=%28-5%2F7%29%28x--3%29\" Plug in \"m=-5%2F7\", \"x%5B1%5D=-3\", and \"y%5B1%5D=3\" (these values are given)
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"y-3=%28-5%2F7%29%28x%2B3%29\" Rewrite \"x--3\" as \"x%2B3\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"y-3=%28-5%2F7%29x%2B%28-5%2F7%29%283%29\" Distribute \"-5%2F7\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"y-3=%28-5%2F7%29x-15%2F7\" Multiply \"-5%2F7\" and \"3\" to get \"-15%2F7\"
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( " \"y=%28-5%2F7%29x-15%2F7%2B3\" Add \"3\" to both sides to isolate y
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"y=%28-5%2F7%29x%2B6%2F7\" Combine like terms \"-15%2F7\" and \"3\" to get \"6%2F7\" (note: if you need help with combining fractions, check out this solver)
\n" ); document.write( "
\n" ); document.write( "
\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 (\"-3\",\"3\") and (\"4\",\"-2\") is:\"y=%28-5%2F7%29x%2B6%2F7\"
\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=-5%2F7\" and the y-intercept is \"b=6%2F7\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " Notice if we graph the equation \"y=%28-5%2F7%29x%2B6%2F7\" and plot the points (\"-3\",\"3\") and (\"4\",\"-2\"), 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=%28-5%2F7%29x%2B6%2F7\" through the points (\"-3\",\"3\") and (\"4\",\"-2\")
\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" );