document.write( "Question 117965: Graph the equation below using the indicated method.
\n" ); document.write( "y= -2/3x +4 by graphing 3 points. \r
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Algebra.Com's Answer #85992 by MathLover1(20850)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "\"y=+-2%2F3x+%2B4\"….this is \"slope-intercept+form\" \r
\n" ); document.write( "\n" ); document.write( "Table with\"+3\" points:\r
\n" ); document.write( "\n" ); document.write( "If \"x=0\" then \"y=+-2%2F3%2A0+%2B4=4\"….\r
\n" ); document.write( "\n" ); document.write( "If \"y=0\" then \"0=+-2%2F3x+%2B4\"….=> \"2%2F3x+=+4\"….=> \"2x+=+12\"….=> \"x+=+6\"\r
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\n" ); document.write( "\n" ); document.write( "If \"x=3\" then \"y=+-%282%2F3%293+%2B4=+-2+%2B4+=+2\"….\r
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\n" ); document.write( "\n" ); document.write( "\"x\" | \"y\"
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\n" ); document.write( "\n" ); document.write( "\"0\" | \"4\"\r
\n" ); document.write( "\n" ); document.write( "\"6\" | \"0\"
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\n" ); document.write( "\"3\" | \"2\"\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 (0, 4)

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  • it has a slope of -(2/3)

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\n" ); document.write( " First, let's draw a diagram of the coordinate system with point (0, 4) 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=-(2/3), and \"system%28+x%5B1%5D+=+0%2C+y%5B1%5D+=+4+%29+\", we have the equation of the line:
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\n" ); document.write( " \"y=-%282%2F3%29%2Ax+%2B+4\"
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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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