Answer:
it is called a decimal system
Step-by-step explanation:
.
Answer:
Perimeter of Triangle: 

Step-by-step explanation:
The perimeter is the sum of all of the sides of the triangle.
Hence, the perimeter 
Since the perimeter is 90,
.
Subtract 15 from both sides:


Divide both sides by 6:


Answer:
Just one of the ones in the numerator and the one in the denominator
Step-by-step explanation:
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:
