x – 3y = -3
x + 3y = 9
x + 3y = 9
-
x – 3y = -3
-3y = -x -3
y = 1/3x + 1
Y intercept = 1
So when graphing start at (0, 1)
Slope = 1/3
Rise over run so go up one unit, three units to the right.
Repeat to graph.
x + 3y = 9
3y = -x + 9
y = -1/3x + 3
Y intercept = 3
So when graphing start at (0, 3)
Slope = -1/3
Down one unit, to the right three units.
Oh to get the ordered pair solution (where they intersect) you just set the two equations equal to each other.
1/3x + 1 = -1/3x + 3
2/3x + 1 = 3
2/3x = 2
2x = 6
x = 3
Then just plug that back into either equation and you'll get y.
3 + 3y = 9
3y = 6
y = 2
(3, 2)
-3y = -x -3
y = 1/3x + 1
Y intercept = 1
So when graphing start at (0, 1)
Slope = 1/3
Rise over run so go up one unit, three units to the right.
Repeat to graph.
x + 3y = 9
3y = -x + 9
y = -1/3x + 3
Y intercept = 3
So when graphing start at (0, 3)
Slope = -1/3
Down one unit, to the right three units.
Oh to get the ordered pair solution (where they intersect) you just set the two equations equal to each other.
1/3x + 1 = -1/3x + 3
2/3x + 1 = 3
2/3x = 2
2x = 6
x = 3
Then just plug that back into either equation and you'll get y.
3 + 3y = 9
3y = 6
y = 2
(3, 2)
-
Download Graph 4.4 from www.padowan.dk for free.
On "Function I Insert relation", type x - 3*y = - 3, then "OK".
On "Function I Insert relation", type x + 3*y = 9,, choose another color, then "OK".
You'll see the lines intersect at (3, 2)
Therefore, the answer is x = 3, y = 2.
On "Function I Insert relation", type x - 3*y = - 3, then "OK".
On "Function I Insert relation", type x + 3*y = 9,, choose another color, then "OK".
You'll see the lines intersect at (3, 2)
Therefore, the answer is x = 3, y = 2.