Answer :
Ex. (4,7) and (8,15)
(15-7)/(8-4)
8/4
2
2 is your slope. To find the y-int plug in one of the coordinates into y=mx+b
7=(2)(4)+b
7=8+b
-1=b
In this example the y-int would be -1.
This method will work for all points
(15-7)/(8-4)
8/4
2
2 is your slope. To find the y-int plug in one of the coordinates into y=mx+b
7=(2)(4)+b
7=8+b
-1=b
In this example the y-int would be -1.
This method will work for all points
[tex]P_1=(x_1,y_1)\ \ \ and\ \ \ P_2=(x_2,y_2)\\\\P_1P_2:\ \ y=mx+b\\\\m= \frac{y_2-y_1}{x_2-x_1} \ \ \ \Rightarrow\ \ \ y=\frac{y_2-y_1}{x_2-x_1}\cdot x+b\\\\for\ P_1:\ \ \ \ \ y_1=\frac{y_2-y_1}{x_2-x_1}\cdot x_1+b\ \ \ \Rightarrow\ \ \ b= y_1-\frac{y_2-y_1}{x_2-x_1}\cdot x_1[/tex]
