Answer:
-1/3 or 1/2.
Step-by-step explanation:
Second term = ar, the third = ar^2 and the fourth = ar^3.
So we have the equation:
ar + ar^2 = 6ar^3
r + r^2 = 6r^3
6r^3 - r^2 - r = 0
r(6r^2 - r - 1) = 0
(3r + 1 )(2r -1) = 0
r = -1/3, 1/2.
17.6
1 book and 7 tenths of another book
