John is 31 and Jenny is 26
Since x is our unknown number, on one side of our equation we will have the "<span>Subtracting two times a number from 10", and on the other will be -3. So,
-3=10-2x</span>
Answer:
7 digits can be used for each position
There are a total of 5 positions
N = 7^5 = 16,807 numbers
You have 7 choices for the first position, second position, etc.
hope helps with the first the rest i cant read its not clear.