Question 122274: What would the coordinates be when solving this system by graphing?
3x + y = 6
3x + y = 0
Answer by algebrapro18(249)   (Show Source):
You can put this solution on YOUR website! 3x + y = 6
3x + y = 0
well first off we need to solve both equations for y, thus putting them into y = mx+b form.
y = -3x +6
y = -3x *Note* this is the same as y = -3x+0
from the equations we can get one set of points just by knowing that the b in y=mx+b is the y-intercept. We know that the first equation crosses the y-axis at (0,6) and the second equation crosses at (0,0). Now we need to find a second set of equations we can use to graph those lines and there are 2(really 3 but 3 good ones)methods for doing this.
Method one- setting both equations equal to zero and solving for x(finding the x-intercept)
-3x+6 =0
-3x = -6
x = 2
-3x=0
x = 0
so the first equation has an x-intercept at (2,0) and the second equation has an x-intercept at (0,0) but since this the same point we got before we will need to use the second method.
Method 2- using the slope
for this all you need to remember is that the slope(m) is rise/run or rYse/run if that will help you remember. That means that for both equations you need to move down 3 in the y direction and over 0 in the x direction from the y-intercept and you will find your second set of points.
(0+0,6-3) = (0,-3)
(0+0, 0-3) = (0,-3)
and now you have your points which are (0,6) and (0,-3) for the first equation and (0,0) and (0, -3) for the second equation. To solve this by graphing you would plot those points and draw a line though each set and see where the two lines intersect.
|
|
|
