Find the constant b so that the three points A(2 , 3), B(4 , 7) and C(8 , b) are collinear (i.e. on the same line).  Pick:
A) 5	B) 10	C) 15	D) 20	E) 25
The slope of the line through A and B must be equal to the slope of the line through B and C.   (7 - 3)/(4- 2) = (b - 7)/(8 - 4)   solve the above for b to find b = 15.   correct answer 15)15
<result>C</result>
Find the constant b so that the three points A(2 , 3), B(4 , 7) and C(8 , b) are collinear (i.e. on the same line).