she will need to mow 8 yards because 109 divided by 15 equals 7.2 but she cant just mow 7.2 yards so you round up to 8 yards
Half one is 1/2;
half three is 3/2;
Thus, if f(x) represents annual growth, f(x)/2 shows it every half-year, like this:

Written in plain text: f(x)=15/2*2^x
Answer: Her e-mail password is 
Step-by-step explanation:
You know that a part of Rivka's e-mail password is formed by the last four digits of her telephone number.
The exercise gives you the last four digits of Rivka's telephone number:

Now, in order to find the other numbers, you need to descompose
into its prime factors. Then:

Therefore, based on this, you can determine that her e-mail password is:

Are there answer choices ?