<PRE><B>Question 21275</B>
Slope of BC is (15-10)/(8--4) = 5/12
To get the intercept choose one of the 
points , say (-4,10) and use the slope.
You then have x=-4,y=10,m=5/12
The line has equation y = mx + b
So, 10 = (5/12)(-4) + b
Then 10 = -5/3 + b
Then b = -35/3
So, the equation of BC is y = (5/12)x - (35/3)

Cheers,
Stan H. </PRE>