document.write( "Question 605506: How do you write an equation from a graph? we are given a square grid with Y axis numbered with 4, 2, 0, -2, -4 and then X axis with -4, -2, 0, 2, 4. and then a line intersecting at y at the 2 and x at the 2. we haven't really tried anything because we don't know where to start. Thanks. \n" ); document.write( "

Algebra.Com's Answer #381721 by Edwin McCravy(20060) $\"\"$ $\"About$

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How do you write an equation from a graph? we are given a square grid with Y axis numbered with 4, 2, 0, -2, -4 and then X axis with -4, -2, 0, 2, 4. and then a line intersecting at y at the 2 and x at the 2. we haven't really tried anything because we don't know where to start. Thanks.
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document.write( "First watch this video:\r\n" );
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document.write( "http://www.youtube.com/watch?v=Mbd-wT0aMQ0&feature=related\r\n" );
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document.write( "After watching that, then continue:\r\n" );
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document.write( "This is what you have:\r\n" );
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document.write( "Start at the y-intercept and draw a line straight down any arbitrary\r\n" );
document.write( "number of blocks, say 3 units straight down vertically, like this \r\n" );
document.write( "green arrow  below:\r\n" );
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document.write( "Now starting at that arrowhead, draw another green arrow over to the \r\n" );
document.write( "right over to the line, like this:\r\n" );
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document.write( "1.  We find the slope, which is a fraction,   \r\n" );
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document.write( "    A. The numerator (rise) of the slope fraction is equal to the length \r\n" );
document.write( "       of the first arrow, the vertical one going down. Its length is 3, but \r\n" );
document.write( "       since the arrow went DOWN instead of up, the numerator, of the\r\n" );
document.write( "       slope is NEGATIVE, so it's -3.\r\n" );
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document.write( "    B. The denominator (run) of the slope fraction is equal to the length \r\n" );
document.write( "       of the second arrow, the horizontal one going right. Its length is 3,\r\n" );
document.write( "       and since the arrow went RIGHT instead of left, the denominator of the\r\n" );
document.write( "       slope is POSITIVE, so it's +3.\r\n" );
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document.write( "    C. So the slope is the fraction  which reduces to -1.\r\n" );
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document.write( "    D. We use the letter \"m\" to represent ths slope so, m = -1\r\n" );
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document.write( "2.  We observe the y-intercept, \r\n" );
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document.write( "    1.  This is the number on the y-axis where the line crosses the y-axis.\r\n" );
document.write( "        That number is 2.\r\n" );
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document.write( "    2.  We use the letter \"b\" to stand for the number on th y-axis where\r\n" );
document.write( "        the line crosses the y-axis. \r\n" );
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document.write( "3.  We substitute the values for \"m\" and \"b\" in the slope-intecept\r\n" );
document.write( "    formula, which is\r\n" );
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document.write( "        y = mx + b\r\n" );
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document.write( "    We substitute the values m=-1 and b=2 into that equation:\r\n" );
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document.write( "        y = -1x + 2\r\n" );
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document.write( "4.  That is the equation of the line. We don't have to write the 1, and\r\n" );
document.write( "    just write\r\n" );
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document.write( "         y = -x + 2\r\n" );
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document.write( "Edwin

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