document.write( "Question 215585: what is the y intercept of the points (1, 202) and (4, 382)? \n" ); document.write( "
Algebra.Com's Answer #162893 by drj(1380)\"\" \"About 
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What is the y intercept of the points (1, 202) and (4, 382)?\r
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\n" ); document.write( "\n" ); document.write( "Step 1. We need to find an equation in slope intercept form given as y=mx+b where m is the slope and b is the y-intercept 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=1, y1=202, x2=4 and y2=382 (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=%28382-202%29%2F%284-1%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"m=180%2F3\"\r
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\n" ); document.write( "\n" ); document.write( "\"m=60\"\r
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\n" ); document.write( "\n" ); document.write( "Step 4. The slope is calculated as 60 or m=60.\r
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\n" ); document.write( "\n" ); document.write( "Step 5. Now use the slope equation of step 1 and choose one of the given points. I'll choose point (1,202). Letting y=y2 and x=x2 and substituting m=60 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( "\"+60=%28y-202%29%2F%28x-1%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"+60=%28y-202%29%2F%28x-1%29\"\r
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\n" ); document.write( "\n" ); document.write( "Step 6. Multiply both sides of equation by x-1 to get rid of denomination found on the right side of the equation\r
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\n" ); document.write( "\n" ); document.write( "\"+60%28x-1%29=%28x-1%29%28y-202%29%2F%28x-1%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"+60x-60=y-202\"\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( "\"60x-60=y-202\"\r
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\n" ); document.write( "\n" ); document.write( "Add 202 to both sides of the equation\r
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\n" ); document.write( "\n" ); document.write( "\"60x-60%2B202=y-202%2B202\"\r
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\n" ); document.write( "\n" ); document.write( "\"60x%2B142=y\"\r
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\n" ); document.write( "\n" ); document.write( "\"y=60x%2B142\" ANSWER in slope-intercept form. m=60 and y-intercept=142\r
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\n" ); document.write( "\n" ); document.write( "Step 8. See if the other point (4, 382) or x=4 and y=382 satisfies this equation\r
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\n" ); document.write( "\n" ); document.write( "\"y=60x%2B142\"\r
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\n" ); document.write( "\n" ); document.write( "\"382=60%2A4%2B142\"\r
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\n" ); document.write( "\n" ); document.write( "{{382=382}}} So the point (4,382) 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( "Note: above equation can be also be transform into standard form as\r
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\n" ); document.write( "\n" ); document.write( "\"-60x%2By=142\"\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 \"-60+x+%2B+1+y+=+142\" describes a sloping line. For any
\n" ); document.write( " equation ax+by+c = 0, slope is \"-a%2Fb+=+--60%2F1\".
  • X intercept is found by setting y to 0: ax+by=c becomes ax=c. that means that x = c/a. 142/-60 = -2.36666666666667.
  • Y intercept is found by setting x to 0: the equation becomes by=c, and therefore y = c/b. Y intercept is 142/1 = 142.
  • Slope is --60/1 = 60.
  • Equation in slope-intercept form: y=60*x+142.
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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( "And good luck in your studies!\r
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\n" ); document.write( "\n" ); document.write( "For free Step-By-Step Videos on Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra or for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.\r
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\n" ); document.write( "\n" ); document.write( "Respectfully,
\n" ); document.write( "Dr J
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