Answer:
B. 9
Step-by-step explanation:
We assume that ...
SU = ST +TU
133 = (9x-5) +(5x+12)
126 = 14x . . . . . subtract 7, collect terms
9 = x . . . . . . . . . divide by 14
4/7 = 8/14 = 12/21 = 16/28, etc
Elga's age = x
Alvin's age = x + 7
x + x + 7 = 97.
Simplify the left side of the equation
2x + 7 = 97.
Subtract 7 from each side
2x = 90.
Divide each side by 2
x = 45
Since x is equal to Elga's age, Elga is 45 years old
Answer:
Use multitape Turing machine to simulate doubly infinite one
Explanation:
It is obvious that Turing machine with doubly infinite tape can simulate ordinary TM. For the other direction, note that 2-tape Turing machine is essentially itself a Turing machine with doubly (double) infinite tape. When it reaches the left-hand side end of first tape, it switches to the second one, and vice versa.
