Let's say the TV costs x dollars BEFORE the discount.

Jack's cashier took 10% off the price and then added 8.5% sales tax
Jack's cashier took 10% off the price... so, the discounted price = (0.9)x
....and then added 8.5% sales tax. Adding 8.5% tax is the same as multiplying by 1.085
So., Jack's final cost = (0.9)(x)(1.085)

Jill's cashier first added the tax and then took 10% off the total price.
Jill's cashier first added the tax... adding 8.5% tax is the same as multiplying by 1.085
So, the new cost is (1.085)(x)
....and then took 10% off the total price.
So, Jill's final cost = (0.9)(1.085)(x)

We get:
Quantity A: (0.9)(x)(1.085)
Quantity B: (0.9)(1.085)(x)

Answer: