10(4^2-(9)
Since 16-9 is 7
And 10 times 7 is 70
Step-by-step explanation:

Answer:
It is divisible by 11 and (a + b) !
Step-by-step explanation:
Given a two digit number
, the digits written in reverse order is
.
Note that a two digit number ab = 10a + b.
For example: 24 = 10(2) + 4
Similarly, ba = 10(b) + a
Now, the sum of the numbers ab and ba = 10a + b + 10b + a
= 11a + 11b
= 11(a + b)
Hence, the sum of any two digit number ab and the reverse of the number ba, is divisible by 11 and (a + b).
Hence, proved.
The problem does not clearly give us the distance from Buffalo to Chicago, so let this be x (in mile) just so I can show you how the total cost is solved.
The total cost is equal to the sum of the rental fee plus the cost of the additional fee per mile which is equal to 1.50x, and also of the cost of the gasoline which is equal to (x/16)(2.15). Thus, the final answer should be expressed as,
total cost = 29.95 + 1.5x + 2.15x/16
When the distance is available, this should be easily substituted in the equation above.
The answer is the third option, it will run out in 8 days.