document.write( "Question 1125239: find the equation of the line P1(0,3) P2(-1,0) \n" ); document.write( "
Algebra.Com's Answer #741536 by MathLover1(20850)\"\" \"About 
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Solved by pluggable solver: Finding the Equation of a Line
First lets find the slope through the points (\"0\",\"3\") and (\"-1\",\"0\")
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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 (\"0\",\"3\") and (\"x%5B2%5D\",\"y%5B2%5D\") is the second point (\"-1\",\"0\"))
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\n" ); document.write( " \"m=%280-3%29%2F%28-1-0%29\" Plug in \"y%5B2%5D=0\",\"y%5B1%5D=3\",\"x%5B2%5D=-1\",\"x%5B1%5D=0\" (these are the coordinates of given points)
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\n" ); document.write( " \"m=+-3%2F-1\" Subtract the terms in the numerator \"0-3\" to get \"-3\". Subtract the terms in the denominator \"-1-0\" to get \"-1\"
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\n" ); document.write( " \"m=3\" Reduce
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\n" ); document.write( " So the slope is
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\n" ); document.write( " \"m=3\"
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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=%283%29%28x-0%29\" Plug in \"m=3\", \"x%5B1%5D=0\", and \"y%5B1%5D=3\" (these values are given)
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\n" ); document.write( " \"y-3=3x%2B%283%29%280%29\" Distribute \"3\"
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\n" ); document.write( " \"y-3=3x%2B0\" Multiply \"3\" and \"0\" to get \"0%2F1\". Now reduce \"0%2F1\" to get \"0\"
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\n" ); document.write( " \"y=3x%2B0%2B3\" Add \"3\" to both sides to isolate y
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\n" ); document.write( " \"y=3x%2B3\" Combine like terms \"0\" and \"3\" to get \"3\"
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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 (\"0\",\"3\") and (\"-1\",\"0\") is:\"y=3x%2B3\"
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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=3\" and the y-intercept is \"b=3\"
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\n" ); document.write( " Notice if we graph the equation \"y=3x%2B3\" and plot the points (\"0\",\"3\") and (\"-1\",\"0\"), we get this: (note: if you need help with graphing, check out this solver)
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\n" ); document.write( " Graph of \"y=3x%2B3\" through the points (\"0\",\"3\") and (\"-1\",\"0\")
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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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