Answer:
a = -7/23.
Step-by-step explanation:
For them to lie on the same line the slope of the line joining the first 2 points must equal the slope of the line joining the second and third points.
so (3 - -5) / (-a+2 - 3) = (2 - 3) /[(2a + 3) - (-a + 2)]
8 / (-a - 1) = -1 / (3a + 1) Cross multiply:
-1(-a - 1) = 8(3a + 1)
a + 1 = 24a + 8
-7 = 23a
a = -7/23.
