SOLUTION: Graph 2x – y = 4

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Question 92958: Graph 2x – y = 4
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Solved by pluggable solver: Graphing Linear Equations


2%2Ax-1%2Ay=4Start with the given equation



-1%2Ay=4-2%2Ax Subtract 2%2Ax from both sides

y=%28-1%29%284-2%2Ax%29 Multiply both sides by -1

y=%28-1%29%284%29%2B%281%29%282%29x%29 Distribute -1

y=-4%2B%282%29x Multiply

y=2%2Ax-4 Rearrange the terms

y=2%2Ax-4 Reduce any fractions

So the equation is now in slope-intercept form (y=mx%2Bb) where m=2 (the slope) and b=-4 (the y-intercept)

So to graph this equation lets plug in some points

Plug in x=-2

y=2%2A%28-2%29-4

y=-4-4 Multiply

y=-8 Add

So here's one point (-2,-8)





Now lets find another point

Plug in x=-1

y=2%2A%28-1%29-4

y=-2-4 Multiply

y=-6 Add

So here's another point (-1,-6). Add this to our graph





Now draw a line through these points

So this is the graph of y=2%2Ax-4 through the points (-2,-8) and (-1,-6)


So from the graph we can see that the slope is 2%2F1 (which tells us that in order to go from point to point we have to start at one point and go up 2 units and to the right 1 units to get to the next point) the y-intercept is (0,-4)and the x-intercept is (2,0) . So all of this information verifies our graph.


We could graph this equation another way. Since b=-4 this tells us that the y-intercept (the point where the graph intersects with the y-axis) is (0,-4).


So we have one point (0,-4)






Now since the slope is 2%2F1, this means that in order to go from point to point we can use the slope to do so. So starting at (0,-4), we can go up 2 units


and to the right 1 units to get to our next point



Now draw a line through those points to graph y=2%2Ax-4


So this is the graph of y=2%2Ax-4 through the points (0,-4) and (1,-2)