Hi again L;
y = x + 1
y = 3x + 9
Both equations are in SLOPEINTERCEPT FORMAT...
y=mx+b
m is the slope.
b is the yintercept, the value of y when x=0.
FIRST EQUATION...
y = x + 1
Slope, m, is 1.
Yintercept, b, is 1.
SECOND EQUATION...
y = 3x + 9
Slope, m, is 3.
Yintercept, b, is 9.
It would be helpful to know at what point the two lines intersect. Let's subtract the second equation from the first. We could subtract the first equation from the second. I randomly select this arrangement...
y = x + 1
(y = 3x + 9)
0=4x8
Let's subtract 4x from both sides...
4x+0=4x4x8
4x=8
x=2
Let's plugin x into either equation to solve for y. I randomly select the first...
y = x + 1
y=2+1
y=3
Let's check our results with the second equation...
y = 3x + 9
3=[(3)(2)]+9
3=6+9
3=3
The lines intersect at coordinate (2,3).
12/28/2013

Vivian L.