document.write( "Question 69982: Find the slope and y-intercept.
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\n" ); document.write( "(D) Slope: 0; y-intercept: (0, –7)
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Algebra.Com's Answer #49839 by Edwin McCravy(20055)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Find the slope and y-intercept.\r\n" );
document.write( "x = –7\r\n" );
document.write( "is it:\r\n" );
document.write( "(A) Slope: undefined; y-intercept: (0, –7)\r\n" );
document.write( "(B) Slope: 0; y-intercept: none\r\n" );
document.write( "(C) Slope: undefined; y-intercept: none\r\n" );
document.write( "(D) Slope: 0; y-intercept: (0, –7)\r\n" );
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document.write( "Draw the graph:  Think of it as \r\n" );
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document.write( "x + 0y = -7\r\n" );
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document.write( "Find some points.  \r\n" );
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document.write( "Arbitrarily substitute 3 for y\r\n" );
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document.write( "x + 0(3) = -7\r\n" );
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document.write( "       x = -7\r\n" );
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document.write( "So one point on the line is (-7, 3)\r\n" );
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document.write( "Arbitrarily substitute -4 for y\r\n" );
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document.write( "x + 0(-4) = -7\r\n" );
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document.write( "        x = -7\r\n" );
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document.write( "So another point on the line is (-7, -4)\r\n" );
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document.write( "Plot those two points and draw a line through them:\r\n" );
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document.write( "\"+graph%28+260%2C+200%2C+-10%2C+3%2C+-5%2C+5%2C+999%28x%2B7%29%29+\"\r\n" );
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document.write( "As you can see it doesn't have a y-intercept because\r\n" );
document.write( "it is parallel to the y-axis and doesn't intercept it\r\n" );
document.write( "at all.  \r\n" );
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document.write( "It does have an x-intercept at (-7,0)\r\n" );
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document.write( "If we try to find its slope with the slope formula\r\n" );
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document.write( "     y2 - y1\r\n" );
document.write( "m = —————————\r\n" );
document.write( "     x2 - x1\r\n" );
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document.write( "using the two points we found (-7, 3), (-7, -4)\r\n" );
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document.write( "where (x1, y1) = (-7, 3) and (x2, y2) = (-7, -4), we get\r\n" );
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document.write( "     (-4) - (3)     -4 - 3     -7\r\n" );
document.write( "m = ———————————— = ———————— = ———— \r\n" );
document.write( "    (-7) - (-7)     -7 + 7      0 \r\n" );
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document.write( "Division by 0 is undefined so the\r\n" );
document.write( "slope is undefined.\r\n" );
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document.write( "The correct choice is \r\n" );
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document.write( "(C) Slope: undefined; y-intercept: none\r\n" );
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document.write( "Edwin
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