Question 74204
There are several ways to go about graphing this function. One way is to replace f(x) with y 
that you get the equation:
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y = -2x -5
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Now all you need to do is to assume values for x and calculate the corresponding values for y.
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For example, if you let x be zero the equation reduces to:
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y = 0 - 5 = -5.
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So a (x,y) point on the graph is (0,-5).  Plot it.
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Then assume another value of x.  For example, Let x = 5.  Substitute it into the equation and 
you get:
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y = (-2)*(5) - 5 = -10 - 5 = -15. 
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So another (x,y) point on the graph is (5,-15). Plot it also.
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Try one more.  Let x = -5.  Substitute that into the equation and you get:
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y = (-2)*(-5) - 5 = 10 -5 = +5.
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So a third (x,y) point is (-5,+5). Plot it.
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All three points should lie in a straight line.  Put a straight edge on them and extend a line
through them.  That is the graph.
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Another way to graph y = -2x - 5 is to recognize that this equation is in the slope-intercept 
form of y = mx + b where m, the multiplier of x, is the slope and b is the value at which the
graph crosses the y-axis.  Comparing the slope-intercept form with the given equation allows
you to see that m must equal -2 and b must equal -5.  This means that the graph crosses the
y-axis at y = -5 and it has a slope of -2.  That means that you can put your pencil on
the y-intercept point (on the y-axis at -5) then move your pencil 1 unit horizontally
to the right, stop there, then go vertically down 2 units (the slope is -2 and the minus
sign means move down). When you get there put a dot. That will be a point on the graph.
From that point you can again move to the right 1 horizontal unit then down 2 vertical units
and mark that point.  That's a third point on the graph.
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And when you get done with these two different methods you should find that your graph looks like
this:
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{{{graph(600,600,-20,20,-20,20,-2x -5)}}}
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Hope this helps you with graphing slope-intercept type equations.