Question
Question: If the points (–2,–5), (2,–2), (8,a) are collinear, then the value of a is....
If the points (–2,–5), (2,–2), (8,a) are collinear, then the value of a is.
A
−25
B
25
C
23
D
21
Answer
25
Explanation
Solution
Let A be (– 2, – 5), B (2, –2) and C is (8, a), we know that, three points are collinear if slope of AB = slope of BC ⇒2+2−2+5=8−2a+2⇒a=25 .