document.write( "Question 85242: Write the equation of the line with x-intercept (–3, 0) and y-intercept (0, –2). \n" ); document.write( "
Algebra.Com's Answer #61440 by jim_thompson5910(35256)\"\" \"About 
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Since we know the intercepts, we know 2 points on the line. So we have the points (-3,0) and (0,-2)\r
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Solved by pluggable solver: Finding the Equation of a Line
First lets find the slope through the points (\"-3\",\"0\") and (\"0\",\"-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 (\"-3\",\"0\") and (\"x%5B2%5D\",\"y%5B2%5D\") is the second point (\"0\",\"-2\"))
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\n" ); document.write( " \"m=%28-2-0%29%2F%280--3%29\" Plug in \"y%5B2%5D=-2\",\"y%5B1%5D=0\",\"x%5B2%5D=0\",\"x%5B1%5D=-3\" (these are the coordinates of given points)
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\n" ); document.write( " \"m=+-2%2F3\" Subtract the terms in the numerator \"-2-0\" to get \"-2\". Subtract the terms in the denominator \"0--3\" to get \"3\"
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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-0=%28-2%2F3%29%28x--3%29\" Plug in \"m=-2%2F3\", \"x%5B1%5D=-3\", and \"y%5B1%5D=0\" (these values are given)
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\n" ); document.write( " \"y-0=%28-2%2F3%29%28x%2B3%29\" Rewrite \"x--3\" as \"x%2B3\"
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\n" ); document.write( " \"y-0=%28-2%2F3%29x%2B%28-2%2F3%29%283%29\" Distribute \"-2%2F3\"
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\n" ); document.write( " \"y-0=%28-2%2F3%29x-2\" Multiply \"-2%2F3\" and \"3\" to get \"-6%2F3\". Now reduce \"-6%2F3\" to get \"-2\"
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\n" ); document.write( " \"y=%28-2%2F3%29x-2%2B0\" Add \"0\" to both sides to isolate y
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\n" ); document.write( " \"y=%28-2%2F3%29x-2\" Combine like terms \"-2\" and \"0\" to get \"-2\"
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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 (\"-3\",\"0\") and (\"0\",\"-2\") is:\"y=%28-2%2F3%29x-2\"
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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=-2\"
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\n" ); document.write( " Notice if we graph the equation \"y=%28-2%2F3%29x-2\" and plot the points (\"-3\",\"0\") and (\"0\",\"-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=%28-2%2F3%29x-2\" through the points (\"-3\",\"0\") and (\"0\",\"-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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