Question 1110743:  Question: Graph the lines x=0, x=6, y=0 and y=x+4. Find the area of the quadrilateral formed.
 
I'm clear on graphing x=0, x=6 and y=0. I'm also clear on how to find the area.
 
For whatever reason I'm having trouble understanding the graphing of y=x+4. I know that y=x+4 is a diagonal that goes though (0, 4) & (6, 10) - (i have the the graph that has been solved by another party, without explanation). Please explain how I get the diagonal that passes though points (0, 4) & (6, 10)?
 
Thanks 
 Answer by jim_thompson5910(35256)      (Show Source): 
You can  put this solution on YOUR website!  
The letters x and y are simply placeholders for numbers. When we say x+4 we mean "some number plus 4". So for example, we can replace x with 0 to go from x+4 to 0+4.
 
 
If we do so, then we will have... 
y = x+4 
y = 0+4 
y = 4 
So x = 0 pairs up with y = 4. They form the ordered pair (0,4) 
The term "point" is a shorter term for "ordered pair" 
The first value is the x value; the second coordinate is the y value 
All ordered pairs or points are of the form (x,y)
 
 
If we replaced x with 6, then we would have y equal to... 
y = x+4 
y = 6+4 
y = 10 
So another ordered pair is (6,10)
 
 
Now plot the two points (0,4) and (6,10).  
They are marked as point A and point B respectively 
  
The point (0,4) is the y intercept as it is on the y axis. We get to this point by moving 4 units up from the origin 
The point (6,10) is located by starting at the origin, then moving 6 units to the right and finally 10 units up.
 
 
Then draw a straight line through those two points. This line extends infinitely in both directions 
  
Notes: 
The slope of y = x+4 is 1 because y = x+4 is the same as y = 1x+4. It is in the form y = mx+b where m is the slope 
The y intercept is b = 4 which is where the red graph crosses the vertical y axis. 
 
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