document.write( "Question 265574: Find an equation of the line containing the given pair of points. Express the anser in the form x=a, y=b, or y=mx+b (-3,-3)and (5,5) \n" ); document.write( "

Algebra.Com's Answer #195304 by dabanfield(803) $\"\"$ $\"About$

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Find an equation of the line containing the given pair of points. Express the anser in the form x=a, y=b, or y=mx+b (-3,-3)and (5,5)\r
\n" ); document.write( "\n" ); document.write( "The slope of the line between the teo points is the difference in y values divided by the difference in x values:\r
\n" ); document.write( "\n" ); document.write( "m = [5-(-3)]/(5-(-3)]
\n" ); document.write( "m = 8/8 = 1\r
\n" ); document.write( "\n" ); document.write( "The slope intercept form of a line is y = mx + b so the equation for this line in slope-intercept form is:\r
\n" ); document.write( "\n" ); document.write( "y = 1*x + b\r
\n" ); document.write( "\n" ); document.write( "Since the point (5,5) lies on the line we know that when x=5, y also equals 5 so we can substitute x=5 and y=5 in the equation above and solve for b:\r
\n" ); document.write( "\n" ); document.write( "5 = 1*5 + b
\n" ); document.write( "b = 0\r
\n" ); document.write( "\n" ); document.write( "The equation for the line is then y = 1*x + 0 or y = x.\r
\n" ); document.write( "\n" ); document.write( "Notice if we had chosen the other point (-3,-3) we would also have had:\r
\n" ); document.write( "\n" ); document.write( "-3 = 1*-3 + b
\n" ); document.write( "-3 = -3 + b
\n" ); document.write( "b = 0 \n" ); document.write( "

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