document.write( "Question 246192: Find an equation of the line containing the given pair of points. (1/4, -1/2) and (3/4,2). \n" ); document.write( "
Algebra.Com's Answer #179833 by oberobic(2304)\"\" \"About 
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Our two points are:
\n" ); document.write( "(1/4, -1/2) = (x1, y1)
\n" ); document.write( "(3/4, 2) = (x2, y2)\r
\n" ); document.write( "\n" ); document.write( "We know y = mx + b
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\n" ); document.write( "m = rise/run = change in y divided by change in x
\n" ); document.write( "change in y = y2 - y1 = 2 - (-1/2) = 2 + 1/2= 2.5
\n" ); document.write( "change in x = x2 - x1 = 3/4 - 1/4 = 1/2 = .5
\n" ); document.write( "m = 2.5/.5 = 5
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\n" ); document.write( "We are given the points above, so we can substitute into y=mx+b
\n" ); document.write( "2 = 5(3/4) + b
\n" ); document.write( "2 = 15/4 + b
\n" ); document.write( "2 - 15/4 = b
\n" ); document.write( "b = 2 - 15/4 = 8/4 - 15/4 = -7/4 = -1.75
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\n" ); document.write( "We also can use the other equation to find b as a check.
\n" ); document.write( "-1/2 = 5(1/4) + b
\n" ); document.write( "-.5 = 1.25 + b
\n" ); document.write( "-1.75 = b
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\n" ); document.write( "We can graph this line:
\n" ); document.write( "\"graph%28500%2C500%2C-3%2C3%2C-3%2C3%2C5%2Ax-1.75%29\" \n" ); document.write( "
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