The three points, (3, -5), (-a +2, 3), (2a+3, 2), lie on the same line. What is a?
+128406 The slope between any two points is constant
Therefore
Slope between first two points = slope between first and third point
(3 - - 5) / ( -a + 2 - 3) = (2 - - 5) /( 2a + 3 - 3) simplify
(8) / ( -a - 1) = ( 7) / ( 2a) cross-multiply
8 * 2a = 7 (-a - 1)
16a = -7a - 7 add 7a to both sides
23a = -7
a = -7/23
