document.write( "Question 70206: Find the equation of the line passing through the points {1/5 , 7} , {-2 , 4}.\r
\n" ); document.write( "\n" ); document.write( "My problem here is that I don't know how to change the given point 1/5 into a whole number.
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Algebra.Com's Answer #50076 by bucky(2189)\"\" \"About 
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Find the equation of the line passing through the points {1/5 , 7} , {-2 , 4}.
\n" ); document.write( ".
\n" ); document.write( "You don't need to convert the \"1%2F5\" into a \"whole number\", but maybe it would help you
\n" ); document.write( "to change it to its equivalent decimal form which is 0.2 [you can do that conversion
\n" ); document.write( "by dividing 5 into 1.0]\r
\n" ); document.write( "\n" ); document.write( "If you make that conversion your points are (0.2, 7}, {-2, 4}. Call the first point
\n" ); document.write( "(x1, y1) and the second point (x2, y2). By comparing these with the given information
\n" ); document.write( "you can see that
\n" ); document.write( "x1 = 0.2
\n" ); document.write( "x2 = -2
\n" ); document.write( "y1 = 7
\n" ); document.write( "y2 = 4\r
\n" ); document.write( "\n" ); document.write( "The slope of the line joining the two points can be found from the formula:
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\n" ); document.write( "\"%28y2-y1%29%2F%28x2-x1%29\"
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\n" ); document.write( "Substitute the values for x1, x2, y1, and y2 in the appropriate places of the slope equation
\n" ); document.write( "to get
\n" ); document.write( "\"%284+-+7%29%2F%28-2+-+0.2%29\"
\n" ); document.write( "This simplifies to:
\n" ); document.write( "\"-3%2F-2.2=1.363636\"
\n" ); document.write( "and we normally use m to represent the slope. Therefore, you can say m = 1.363636
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\n" ); document.write( "\n" ); document.write( "You can now write the equation using:\r
\n" ); document.write( "\n" ); document.write( "\"m+=+%28y-y1%29%2F%28x-x1%29\"\r
\n" ); document.write( "\n" ); document.write( "and substitute for m, y1, and x1 to get:\r
\n" ); document.write( "\n" ); document.write( "\"1.363636+=+%28y-7%29%2F%28x-0.2%29\"\r
\n" ); document.write( "\n" ); document.write( "as the equation.\r
\n" ); document.write( "\n" ); document.write( "But if you wanted to stay with the fraction 1/5 as x1, you could write that the
\n" ); document.write( "slope m is:\r
\n" ); document.write( "\n" ); document.write( "\"m+=+%28y2-y1%29%2F%28x2-x1%29+=+%284-7%29%2F%28-2-%281%2F5%29%29+=+-3%2F%28-2-%281%2F5%29%29\"
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\n" ); document.write( "You can now work on the value of \"-2-%281%2F5%29\". Recognize that 2 is the same as \"10%2F5\"
\n" ); document.write( "so you can make that substitution to get
\n" ); document.write( "\"-2-%281%2F5%29+=+%28-10%2F5%29-%281%2F5%29+=+-11%2F5\"
\n" ); document.write( "Substitute that into the slope equation to get:\r
\n" ); document.write( "\n" ); document.write( "\"m+=+-3%2F%28-11%2F5%29\" \r
\n" ); document.write( "\n" ); document.write( "Do the division by inverting the denominator and multiplying this inversion times the
\n" ); document.write( "numerator:\r
\n" ); document.write( "\n" ); document.write( "\"+m+=+-3%2A%28-5%2F11%29+=+15%2F11\"
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\n" ); document.write( "Use the value
\n" ); document.write( "\"15%2F11\"
\n" ); document.write( "for m and substitute it into the equation along with the substitutions
\n" ); document.write( "for x1 and y1 to get:
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\n" ); document.write( "\"m+=+%28y-y1%29%2F%28x-x1%29\"
\n" ); document.write( ".
\n" ); document.write( "\"%2815%2F11%29+=+%28y-7%29%2F%28x-%281%2F5%29%29\"
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\n" ); document.write( "This is an equivalent form of the answer above that uses decimals in the equation.\r
\n" ); document.write( "\n" ); document.write( "Study this carefully. Hopefully it will give you some insight into working with fractions
\n" ); document.write( "in writing equations.
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