document.write( "Question 1203958: hello! i need help! i am trying to solve a word problem but i can't figure it out! the word problem is: \"the number of acres of farmland in the US has decreased at a relatively constant rate of 3.27 million acres per year from 1987 to 1997. in 1997, there were 931.8 million acres of farmland.\" i have to write an equation that gives the number of acres of farmland as a function of the number of years since 1987. then i have to predict when the number of acres will fall below 915 million acres.
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Algebra.Com's Answer #839977 by MathTherapy(10552)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "hello! i need help! i am trying to solve a word problem but i can't figure it out! the word problem is: \"the number of acres of farmland in the US has decreased at a relatively constant rate of 3.27 million acres per year from 1987 to 1997. in 1997, there were 931.8 million acres of farmland.\" i have to write an equation that gives the number of acres of farmland as a function of the number of years since 1987. then i have to predict when the number of acres will fall below 915 million acres.\r\n" );
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document.write( "Initial year: 1987, which is treated as YEAR 0. Coordinate point: (0, y1). \r\n" );
document.write( "Subsequent year: 1997, which is 10 YEARS after 1987, the initial year. Coordinate point (10, 931.8), or (x5, y2). \r\n" );
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document.write( "To get your equation, you can use the SLOPE-INTERCEPT form of a linear equation, which is: y = mx + b. Substitute (10, 931.8) for (x, y), and then find the y-intercept, which is also the INITIAL number of acres from the INITIAL year, \r\n" );
document.write( "1987\r\n" );
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document.write( "OR  \r\n" );
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document.write( "Simply use the POINT-SLOPE form of a linear equation, which is: \r\n" );
document.write( "   y - y2 = m(x - x2)  \r\n" );
document.write( "  y - 931.8 = - 3.27(x - 10) ------ Substituting 931.8 for y2,, - 3.27 for m (slope), and 10 for x2\r\n" );
document.write( "y - 931.8 = - 3.27x + 32.7\r\n" );
document.write( "        y = - 3.27x + 32.7 + 931.8 ----- Adding 931.8 to both sides\r\n" );
document.write( "        y = - 3.27x + 964.5 <===== Requested EQUATION\r\n" );
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document.write( "As a prediction is required for the year the number of acres will fall below 915 million acres, \r\n" );
document.write( "the requested EQUATION, y = - 3.27x + 964.5 becomes the following INEQUALITY:\r\n" );
document.write( "- 3.27x + 964.5 < 915 \r\n" );
document.write( "          - 3.27x < 915 - 964.5 \r\n" );
document.write( "          - 3.27x < - 48.5\r\n" );
document.write( "                  \"x+%3E+%28-+48.5%29%2F%28-+3.27%29\" ---- Changing INEQUALITY to its OPPOSITE, since we're DIVIDING by a negative value \r\n" );
document.write( "                  x > 15.1376147.\r\n" );
document.write( "With x being greater than (>) 15.1376147, x = 16 years. So, predicted year after 1987 that the number of acres\r\n" );
document.write( "will fall below 915 million acres is 2003 (1987 + 16).\r\n" );
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document.write( "You can do the CHECK!!
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