document.write( "Question 263: find the equation of the line that contains the points (2,2)and(-4,5). \n" ); document.write( "

Algebra.Com's Answer #114 by terrtwo(10) $\"\"$ $\"About$

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The general equation of a line is y = mx + b. To define a specific line, two things are needed: the slope (m) and the y-intercept (b). From the information given, two points, we are able to determine the slope:\r
\n" ); document.write( "\n" ); document.write( "m = (the change in y)/ (change in x)
\n" ); document.write( "--> $\"m+=+%282-5%29%2F%282+-+%28-4%29%29\"$
\n" ); document.write( "--> m = -3/6 = -1/2\r
\n" ); document.write( "\n" ); document.write( "Then if we use either of the points (let's use the first one listed above, (2,2)) and the slope in the general equation:\r
\n" ); document.write( "\n" ); document.write( "y = mx + b
\n" ); document.write( "--> 2 = -1/2*2 +b
\n" ); document.write( "--> 2 = -1 + b\r
\n" ); document.write( "\n" ); document.write( "Add 1 to both side:
\n" ); document.write( "--> 2 + 1 = -1 + b + 1
\n" ); document.write( "--> 3 = b\r
\n" ); document.write( "\n" ); document.write( "Now to define the equation of the line we substitute in JUST the m and b:\r
\n" ); document.write( "\n" ); document.write( "y = mx + b
\n" ); document.write( "--> y = -1/2*x + 3
\n" ); document.write( "ANSWER \n" ); document.write( "

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