document.write( "Question 83884: Hello out there,I'm writing for some help with some slope-intercept problems,the first one is,Write the equation in slope-intercept form of the line passing through each pair of points:(-8,2)and(0,6).The next one is,Write the equation in slope-intercept form of the line passing through each pair of points :(6,-2)and (3,-4).Next is,Write an equation in slope-intercept form of the line having the given slope and passing through the given point:m=0,(0,-3).And the last one is,Write the point-slope form of the line that passes through (3,-3)and (5,1),thanks for whoever can help. \n" ); document.write( "
Algebra.Com's Answer #60383 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
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Solved by pluggable solver: Finding the Equation of a Line
First lets find the slope through the points (\"-8\",\"2\") and (\"0\",\"6\")
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\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 (\"-8\",\"2\") and (\"x%5B2%5D\",\"y%5B2%5D\") is the second point (\"0\",\"6\"))
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\n" ); document.write( " \"m=%286-2%29%2F%280--8%29\" Plug in \"y%5B2%5D=6\",\"y%5B1%5D=2\",\"x%5B2%5D=0\",\"x%5B1%5D=-8\" (these are the coordinates of given points)
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\n" ); document.write( " \"m=+4%2F8\" Subtract the terms in the numerator \"6-2\" to get \"4\". Subtract the terms in the denominator \"0--8\" to get \"8\"
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\n" ); document.write( " \"m=1%2F2\" Reduce
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\n" ); document.write( " So the slope is
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\n" ); document.write( " \"m=1%2F2\"
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\n" ); document.write( "Now let's use the point-slope formula to find the equation of the line:
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\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
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\n" ); document.write( " So lets use the Point-Slope Formula to find the equation of the line
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\n" ); document.write( " \"y-2=%281%2F2%29%28x--8%29\" Plug in \"m=1%2F2\", \"x%5B1%5D=-8\", and \"y%5B1%5D=2\" (these values are given)
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\n" ); document.write( " \"y-2=%281%2F2%29%28x%2B8%29\" Rewrite \"x--8\" as \"x%2B8\"
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\n" ); document.write( " \"y-2=%281%2F2%29x%2B%281%2F2%29%288%29\" Distribute \"1%2F2\"
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\n" ); document.write( " \"y-2=%281%2F2%29x%2B4\" Multiply \"1%2F2\" and \"8\" to get \"8%2F2\". Now reduce \"8%2F2\" to get \"4\"
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\n" ); document.write( " \"y=%281%2F2%29x%2B4%2B2\" Add \"2\" to both sides to isolate y
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\n" ); document.write( " \"y=%281%2F2%29x%2B6\" Combine like terms \"4\" and \"2\" to get \"6\"
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\n" ); document.write( " Answer:
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\n" ); document.write( " So the equation of the line which goes through the points (\"-8\",\"2\") and (\"0\",\"6\") is:\"y=%281%2F2%29x%2B6\"
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\n" ); document.write( " The equation is now in \"y=mx%2Bb\" form (which is slope-intercept form) where the slope is \"m=1%2F2\" and the y-intercept is \"b=6\"
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\n" ); document.write( " Notice if we graph the equation \"y=%281%2F2%29x%2B6\" and plot the points (\"-8\",\"2\") and (\"0\",\"6\"), we get this: (note: if you need help with graphing, check out this solver)
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\n" ); document.write( " Graph of \"y=%281%2F2%29x%2B6\" through the points (\"-8\",\"2\") and (\"0\",\"6\")
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\n" ); document.write( " Notice how the two points lie on the line. This graphically verifies our answer.
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Solved by pluggable solver: Finding the Equation of a Line
First lets find the slope through the points (\"6\",\"-2\") and (\"3\",\"-4\")
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\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 (\"6\",\"-2\") and (\"x%5B2%5D\",\"y%5B2%5D\") is the second point (\"3\",\"-4\"))
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\n" ); document.write( " \"m=%28-4--2%29%2F%283-6%29\" Plug in \"y%5B2%5D=-4\",\"y%5B1%5D=-2\",\"x%5B2%5D=3\",\"x%5B1%5D=6\" (these are the coordinates of given points)
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\n" ); document.write( " \"m=+-2%2F-3\" Subtract the terms in the numerator \"-4--2\" to get \"-2\". Subtract the terms in the denominator \"3-6\" to get \"-3\"
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\n" ); document.write( " \"m=2%2F3\" Reduce
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\n" ); document.write( " So the slope is
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\n" ); document.write( " \"m=2%2F3\"
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\n" ); document.write( "Now let's use the point-slope formula to find the equation of the line:
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\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
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\n" ); document.write( " So lets use the Point-Slope Formula to find the equation of the line
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\n" ); document.write( " \"y--2=%282%2F3%29%28x-6%29\" Plug in \"m=2%2F3\", \"x%5B1%5D=6\", and \"y%5B1%5D=-2\" (these values are given)
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\n" ); document.write( " \"y%2B2=%282%2F3%29%28x-6%29\" Rewrite \"y--2\" as \"y%2B2\"
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\n" ); document.write( " \"y%2B2=%282%2F3%29x%2B%282%2F3%29%28-6%29\" Distribute \"2%2F3\"
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\n" ); document.write( " \"y%2B2=%282%2F3%29x-4\" Multiply \"2%2F3\" and \"-6\" to get \"-12%2F3\". Now reduce \"-12%2F3\" to get \"-4\"
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\n" ); document.write( " \"y=%282%2F3%29x-4-2\" Subtract \"2\" from both sides to isolate y
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\n" ); document.write( " \"y=%282%2F3%29x-6\" Combine like terms \"-4\" and \"-2\" to get \"-6\"
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\n" ); document.write( " So the equation of the line which goes through the points (\"6\",\"-2\") and (\"3\",\"-4\") is:\"y=%282%2F3%29x-6\"
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\n" ); document.write( " The equation is now in \"y=mx%2Bb\" form (which is slope-intercept form) where the slope is \"m=2%2F3\" and the y-intercept is \"b=-6\"
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\n" ); document.write( " Notice if we graph the equation \"y=%282%2F3%29x-6\" and plot the points (\"6\",\"-2\") and (\"3\",\"-4\"), we get this: (note: if you need help with graphing, check out this solver)
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\n" ); document.write( " Graph of \"y=%282%2F3%29x-6\" through the points (\"6\",\"-2\") and (\"3\",\"-4\")
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\n" ); document.write( " Notice how the two points lie on the line. This graphically verifies our answer.
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Solved by pluggable solver: FIND a line by slope and one point

\n" ); document.write( " What we know about the line whose equation we are trying to find out:
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  • it goes through point (0, -3)

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  • it has a slope of 0

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\n" ); document.write( " First, let's draw a diagram of the coordinate system with point (0, -3) plotted with a little blue dot:
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\n" ); document.write( " Write this down: the formula for the equation, given point \"x%5B1%5D%2C+y%5B1%5D\" and intercept a, is
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\n" ); document.write( " \"y=ax+%2B+%28y%5B1%5D-a%2Ax%5B1%5D%29\" (see a paragraph below explaining why this formula is correct)
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\n" ); document.write( " Given that a=0, and \"system%28+x%5B1%5D+=+0%2C+y%5B1%5D+=+-3+%29+\", we have the equation of the line:
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\n" ); document.write( " \"y=0%2Ax+%2B+-3\"
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\n" ); document.write( " Explanation: Why did we use formula \"y=ax+%2B+%28y%5B1%5D+-+a%2Ax%5B1%5D%29\" ? Explanation goes here. We are trying to find equation y=ax+b. The value of slope (a) is already given to us. We need to find b. If a point (\"x%5B1%5D\", \"y%5B1%5D\") lies on the line, it means that it satisfies the equation of the line. So, our equation holds for (\"x%5B1%5D\", \"y%5B1%5D\"): \"y%5B1%5D+=+a%2Ax%5B1%5D%2Bb\" Here, we know a, \"x%5B1%5D\", and \"y%5B1%5D\", and do not know b. It is easy to find out: \"b=y%5B1%5D-a%2Ax%5B1%5D\". So, then, the equation of the line is: \"+y=ax%2B%28y%5B1%5D-a%2Ax%5B1%5D%29+\".
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\n" ); document.write( "\n" ); document.write( "So the equation is basically \"y=-3\"\r
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Solved by pluggable solver: Finding the Equation of a Line
First lets find the slope through the points (\"3\",\"-3\") and (\"5\",\"1\")
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\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 (\"5\",\"1\"))
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\n" ); document.write( " \"m=%281--3%29%2F%285-3%29\" Plug in \"y%5B2%5D=1\",\"y%5B1%5D=-3\",\"x%5B2%5D=5\",\"x%5B1%5D=3\" (these are the coordinates of given points)
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\n" ); document.write( " \"m=+4%2F2\" Subtract the terms in the numerator \"1--3\" to get \"4\". Subtract the terms in the denominator \"5-3\" to get \"2\"
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\n" ); document.write( " \"m=2\" Reduce
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\n" ); document.write( " So the slope is
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\n" ); document.write( " \"m=2\"
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\n" ); document.write( "Now let's use the point-slope formula to find the equation of the line:
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\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
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\n" ); document.write( " So lets use the Point-Slope Formula to find the equation of the line
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\n" ); document.write( " \"y--3=%282%29%28x-3%29\" Plug in \"m=2\", \"x%5B1%5D=3\", and \"y%5B1%5D=-3\" (these values are given)
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\n" ); document.write( " \"y%2B3=%282%29%28x-3%29\" Rewrite \"y--3\" as \"y%2B3\"
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\n" ); document.write( " \"y%2B3=2x%2B%282%29%28-3%29\" Distribute \"2\"
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\n" ); document.write( " \"y%2B3=2x-6\" Multiply \"2\" and \"-3\" to get \"-6%2F1\". Now reduce \"-6%2F1\" to get \"-6\"
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\n" ); document.write( " \"y=2x-6-3\" Subtract \"3\" from both sides to isolate y
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\n" ); document.write( " \"y=2x-9\" Combine like terms \"-6\" and \"-3\" to get \"-9\"
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\n" ); document.write( " So the equation of the line which goes through the points (\"3\",\"-3\") and (\"5\",\"1\") is:\"y=2x-9\"
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\n" ); document.write( " The equation is now in \"y=mx%2Bb\" form (which is slope-intercept form) where the slope is \"m=2\" and the y-intercept is \"b=-9\"
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\n" ); document.write( " Notice if we graph the equation \"y=2x-9\" and plot the points (\"3\",\"-3\") and (\"5\",\"1\"), we get this: (note: if you need help with graphing, check out this solver)
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\n" ); document.write( " Graph of \"y=2x-9\" through the points (\"3\",\"-3\") and (\"5\",\"1\")
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\n" ); document.write( " Notice how the two points lie on the line. This graphically verifies our answer.
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