document.write( "Question 74204: graph the function.
\n" ); document.write( "f(x) = -2x -5
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Algebra.Com's Answer #53203 by bucky(2189)\"\" \"About 
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There are several ways to go about graphing this function. One way is to replace f(x) with y
\n" ); document.write( "that you get the equation:
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\n" ); document.write( "y = -2x -5
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\n" ); document.write( "Now all you need to do is to assume values for x and calculate the corresponding values for y.
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\n" ); document.write( "For example, if you let x be zero the equation reduces to:
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\n" ); document.write( "y = 0 - 5 = -5.
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\n" ); document.write( "So a (x,y) point on the graph is (0,-5). Plot it.
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\n" ); document.write( "Then assume another value of x. For example, Let x = 5. Substitute it into the equation and
\n" ); document.write( "you get:
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\n" ); document.write( "y = (-2)*(5) - 5 = -10 - 5 = -15.
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\n" ); document.write( "So another (x,y) point on the graph is (5,-15). Plot it also.
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\n" ); document.write( "Try one more. Let x = -5. Substitute that into the equation and you get:
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\n" ); document.write( "y = (-2)*(-5) - 5 = 10 -5 = +5.
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\n" ); document.write( "So a third (x,y) point is (-5,+5). Plot it.
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\n" ); document.write( "All three points should lie in a straight line. Put a straight edge on them and extend a line
\n" ); document.write( "through them. That is the graph.
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\n" ); document.write( "Another way to graph y = -2x - 5 is to recognize that this equation is in the slope-intercept
\n" ); document.write( "form of y = mx + b where m, the multiplier of x, is the slope and b is the value at which the
\n" ); document.write( "graph crosses the y-axis. Comparing the slope-intercept form with the given equation allows
\n" ); document.write( "you to see that m must equal -2 and b must equal -5. This means that the graph crosses the
\n" ); document.write( "y-axis at y = -5 and it has a slope of -2. That means that you can put your pencil on
\n" ); document.write( "the y-intercept point (on the y-axis at -5) then move your pencil 1 unit horizontally
\n" ); document.write( "to the right, stop there, then go vertically down 2 units (the slope is -2 and the minus
\n" ); document.write( "sign means move down). When you get there put a dot. That will be a point on the graph.
\n" ); document.write( "From that point you can again move to the right 1 horizontal unit then down 2 vertical units
\n" ); document.write( "and mark that point. That's a third point on the graph.
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\n" ); document.write( "And when you get done with these two different methods you should find that your graph looks like
\n" ); document.write( "this:
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\n" ); document.write( "Hope this helps you with graphing slope-intercept type equations. \n" ); document.write( "
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