document.write( "Question 701278: find the equation of a line that passes through the point (-1,3) and is parallel to the line passing through the points (-2, -3) and (2,5). THANKS \n" ); document.write( "
Algebra.Com's Answer #432344 by MathLover1(20850)\"\" \"About 
You can put this solution on YOUR website!
first find the equation of the line passing through the points (\"-2\", \"-3\") and (\"2\",\"5\")\r
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Solved by pluggable solver: FIND EQUATION of straight line given 2 points
hahaWe are trying to find equation of form y=ax+b, where a is slope, and b is intercept, which passes through points (x1, y1) = (-2, -3) and (x2, y2) = (2, 5).
\n" ); document.write( " Slope a is \"a+=+%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29+=+%285--3%29%2F%282--2%29+=+2\".
\n" ); document.write( " Intercept is found from equation \"a%2Ax%5B1%5D%2Bb+=+y%5B1%5D\", or \"2%2A-2+%2Bb+=+1\". From that,
\n" ); document.write( " intercept b is \"b=y%5B1%5D-a%2Ax%5B1%5D\", or \"b=-3-2%2A-2+=+1\".
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\n" ); document.write( " y=(2)x + (1)
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\n" ); document.write( " Your graph:
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\n" ); document.write( "\n" ); document.write( "since we are looking for the equation of the line that passes through the point (\"-1\",\"3\") and is parallel to the line \"y=2x%2B1\", we will find it using given point and a slope of \"y=2x%2B1\" which is \"m=2\" because parallel lines have same slope\r
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Solved by pluggable solver: FIND a line by slope and one point

\n" ); document.write( " What we know about the line whose equation we are trying to find out:
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  • it goes through point (-1, 3)

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  • it has a slope of 2

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\n" ); document.write( " First, let's draw a diagram of the coordinate system with point (-1, 3) plotted with a little blue dot:
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\n" ); document.write( " Write this down: the formula for the equation, given point \"x%5B1%5D%2C+y%5B1%5D\" and intercept a, is
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\n" ); document.write( " \"y=ax+%2B+%28y%5B1%5D-a%2Ax%5B1%5D%29\" (see a paragraph below explaining why this formula is correct)
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\n" ); document.write( " Given that a=2, and \"system%28+x%5B1%5D+=+-1%2C+y%5B1%5D+=+3+%29+\", we have the equation of the line:
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\n" ); document.write( " \"y=2%2Ax+%2B+5\"
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\n" ); document.write( " Explanation: Why did we use formula \"y=ax+%2B+%28y%5B1%5D+-+a%2Ax%5B1%5D%29\" ? Explanation goes here. We are trying to find equation y=ax+b. The value of slope (a) is already given to us. We need to find b. If a point (\"x%5B1%5D\", \"y%5B1%5D\") lies on the line, it means that it satisfies the equation of the line. So, our equation holds for (\"x%5B1%5D\", \"y%5B1%5D\"): \"y%5B1%5D+=+a%2Ax%5B1%5D%2Bb\" Here, we know a, \"x%5B1%5D\", and \"y%5B1%5D\", and do not know b. It is easy to find out: \"b=y%5B1%5D-a%2Ax%5B1%5D\". So, then, the equation of the line is: \"+y=ax%2B%28y%5B1%5D-a%2Ax%5B1%5D%29+\".
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\n" ); document.write( " Here's the graph:
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\n" ); document.write( "\n" ); document.write( "so, we found that the lines \"y=2x%2B1\" and \"y=2x%2B5\" are parallel lines, that the line \"y=2x%2B1\" passing through the points (\"-2\", \"-3\") and (\"2\",\"5\"), and the line \"y=2x%2B5\" passing through the point (\"-1\",\"3\")\r
\n" ); document.write( "\n" ); document.write( "see it all on a graph:\r
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