The next term is 1.4 larger than the one before it, so the appropriate choice is

_____
However, the description

also correctly describes the relationship between a1 and a2, for example. While this equation is technically correct, it is less useful to work with, so is probably not the expected answer.
A) 35n + 115
b) 1165
a) 128 - 4n
b)72
Just use an online calculator! i promise you they work better than this.
Answer:

Step-by-step explanation:
Volume of water in the tank = 1000 L
Let y(t) denote the amount of salt in the tank at any time t.
Initially, the tank contains 60 kg of salt, therefore:
y(0)=60 kg
<u />
<u>Rate In</u>
A solution of concentration 0.03 kg of salt per liter enters a tank at the rate 9 L/min.
=(concentration of salt in inflow)(input rate of solution)

<u>Rate Out</u>
The solution is mixed and drains from the tank at the same rate.
Concentration, 
=(concentration of salt in outflow)(output rate of solution)

Therefore, the differential equation for the amount of Salt in the Tank at any time t:

Answer:
b. 3
Step-by-step explanation: