document.write( "Question 226311: Wath is the slope of the line passing through (-5,5) and (9,-9) \n" ); document.write( "
Algebra.Com's Answer #168567 by drj(1380)\"\" \"About 
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Wath is the slope of the line passing through (-5,5) and (9,-9)\r
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\n" ); document.write( "\n" ); document.write( "Step 1. We will put the equation of the line in slope-intercept form given as y=mx+b where m is the slope and b is the y-intercept when x=0 or at point (0,b).\r
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\n" ); document.write( "\n" ); document.write( "Step 2. The slope of the line m is given as\r
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\n" ); document.write( "\n" ); document.write( "\"+m=%28y2-y1%29%2F%28x2-x1%29\"\r
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\n" ); document.write( "\n" ); document.write( "where for our example is x1=-5, y1=5, x2=9 and y2=-9 (think of \"slope=rise%2Frun\"). You can choose the points the other way around but be consistent with the x and y coordinates. You will get the same result.\r
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\n" ); document.write( "\n" ); document.write( "Step 3. Substituting the above values in the slope equation gives\r
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\n" ); document.write( "\n" ); document.write( "\"m=%28-9-5%29%2F%289-%28-5%29%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"m=-14%2F14=-1\"\r
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\n" ); document.write( "\n" ); document.write( "Step 4. The slope is calculated as \"-1\" or \"m=-1\"\r
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\n" ); document.write( "\n" ); document.write( "Step 5. Now use the slope equation of Step 2 and choose one of the given points. I'll choose point (-5,5). Letting y=y2 and x=x2 and substituting \"m=-1\" in the slope equation given as,\r
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\n" ); document.write( "\n" ); document.write( "\"+m=%28y2-y1%29%2F%28x2-x1%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"+-1=%28y-5%29%2F%28x-%28-5%29%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"-1=%28y-5%29%2F%28x%2B5%29\"\r
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\n" ); document.write( "\n" ); document.write( "Step 6. Multiply both sides of equation by x+5 to get rid of denomination found on the right side of the equation\r
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\n" ); document.write( "\n" ); document.write( "\"-%28x%2B5%29=%28x%2B5%29%28y-5%29%2F%28x%2B5%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"+-%28x%2B5%29=y-5\"\r
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\n" ); document.write( "\n" ); document.write( "Step 7. Now simplify and put the above equation into slope-intercept form.\r
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\n" ); document.write( "\n" ); document.write( "\"-x-5=y-5\"\r
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\n" ); document.write( "\n" ); document.write( "Add 5 from both sides of the equation\r
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\n" ); document.write( "\n" ); document.write( "\"-x-5%2B5=y-5%2B5\"\r
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\n" ); document.write( "\n" ); document.write( "\"-x=y\"\r
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\n" ); document.write( "\n" ); document.write( "\"y=-x\" This is in slope-intercept form where the slope m=-1 and y-intercept b=0\r
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\n" ); document.write( "\n" ); document.write( "Step 8. See if the other point (9,-9) or x=9 and y=-9 satisfies this equation\r
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\n" ); document.write( "\n" ); document.write( "\"y=-x\"\r
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\n" ); document.write( "\n" ); document.write( "\"-9=-9\" which is true\r
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\n" ); document.write( "\n" ); document.write( " So the point (9,-9) satisfies the equation and is on the line. In other words, you can use the other point to check your work.\r
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\n" ); document.write( "\n" ); document.write( "Step 9. ANSWER: The equation of the line is \"y=-x\"\r
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\n" ); document.write( "\n" ); document.write( "Note: above equation can be also be transform into standard form as\r
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\n" ); document.write( "\n" ); document.write( "\"x%2By=0\"\r
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\n" ); document.write( "\n" ); document.write( "See graph below to check the above steps.\r
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Solved by pluggable solver: DESCRIBE a linear EQUATION: slope, intercepts, etc
Equation \"1+x+%2B+1+y+=+0\" describes a sloping line. For any
\n" ); document.write( " equation ax+by+c = 0, slope is \"-a%2Fb+=+-1%2F1\".
  • X intercept is found by setting y to 0: ax+by=c becomes ax=c. that means that x = c/a. 0/1 = 0.
  • Y intercept is found by setting x to 0: the equation becomes by=c, and therefore y = c/b. Y intercept is 0/1 = 0.
  • Slope is -1/1 = -1.
  • Equation in slope-intercept form: y=-1*x+0.
\"graph%28+500%2C+500%2C+0-8%2C+0%2B8%2C+0-8%2C+0%2B8%2C+-1%2Ax%2B0+%29+\"\n" ); document.write( "

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\n" ); document.write( "\n" ); document.write( "I hope the above steps were helpful.\r
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\n" ); document.write( "\n" ); document.write( "For FREE Step-By-Step videos in Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra and for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.\r
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\n" ); document.write( "\n" ); document.write( "Good luck in your studies!\r
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\n" ); document.write( "\n" ); document.write( "Respectfully,
\n" ); document.write( "Dr J\r
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