document.write( "Question 472336: Find the equation of the line below. Arrange your answer in the form y = mx + b, where b is the constant. where the coordinates are (2,2) and (-2,-2) \n" ); document.write( "
Algebra.Com's Answer #323845 by MathLover1(20849)\"\" \"About 
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\r
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\n" ); document.write( "\n" ); document.write( "the coordinates are (2,2) and (-2,-2)...find a line that passes through these points\r
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Solved by pluggable solver: Finding the Equation of a Line
First lets find the slope through the points (\"-2\",\"-2\") and (\"2\",\"2\")
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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 (\"-2\",\"-2\") and (\"x%5B2%5D\",\"y%5B2%5D\") is the second point (\"2\",\"2\"))
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\n" ); document.write( " \"m=%282--2%29%2F%282--2%29\" Plug in \"y%5B2%5D=2\",\"y%5B1%5D=-2\",\"x%5B2%5D=2\",\"x%5B1%5D=-2\" (these are the coordinates of given points)
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\n" ); document.write( " \"m=+4%2F4\" Subtract the terms in the numerator \"2--2\" to get \"4\". Subtract the terms in the denominator \"2--2\" to get \"4\"
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\n" ); document.write( " \"m=1\" Reduce
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\n" ); document.write( " So the slope is
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\n" ); document.write( " \"m=1\"
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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%29%28x--2%29\" Plug in \"m=1\", \"x%5B1%5D=-2\", and \"y%5B1%5D=-2\" (these values are given)
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\n" ); document.write( " \"y%2B2=%281%29%28x--2%29\" Rewrite \"y--2\" as \"y%2B2\"
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\n" ); document.write( " \"y%2B2=%281%29%28x%2B2%29\" Rewrite \"x--2\" as \"x%2B2\"
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\n" ); document.write( " \"y%2B2=1x%2B%281%29%282%29\" Distribute \"1\"
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\n" ); document.write( " \"y%2B2=1x%2B2\" Multiply \"1\" and \"2\" to get \"2%2F1\". Now reduce \"2%2F1\" to get \"2\"
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\n" ); document.write( " \"y=1x%2B2-2\" Subtract \"2\" from both sides to isolate y
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\n" ); document.write( " \"y=1x%2B0\" Combine like terms \"2\" and \"-2\" to get \"0\"
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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 (\"-2\",\"-2\") and (\"2\",\"2\") is:\"y=1x%2B0\"
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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\" and the y-intercept is \"b=0\"
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\n" ); document.write( " Notice if we graph the equation \"y=1x%2B0\" and plot the points (\"-2\",\"-2\") and (\"2\",\"2\"), we get this: (note: if you need help with graphing, check out this solver)
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\n" ); document.write( " Graph of \"y=1x%2B0\" through the points (\"-2\",\"-2\") and (\"2\",\"2\")
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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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\n" ); document.write( "\n" ); document.write( "note: the constant \"b=0\"\r
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