Answer:
9th week will have same weight
Step-by-step explanation:
f(x) = 2 * (x +3) Â .... Abe's
f'(x) = 3 * (x - 1) Â Â .... Karen's
∵ f(x) = f'(x)  .... time of two dogs have the same weight
2 * (x +3) = 3 * (x - 1)
2x + 6 = 3x - 3
3x - 2x = 6 + 3
x = 9