
19 and 3 are both prime numbers, and the difference is 16.
What is this supposed to be? Is there any actual question?
The basic idea is that multiplying by 10 just moves the decimal point one place to the right. It makes the number bigger.
Examples:
3.1 x 10 = 31
3.1 x 10 x 10 = 31 x 10 = 310
Each time you multiply by another 10, the decimal point moves one more place.
In your exercise,
says you're going to multiply by 10 <u>three</u> times in a row. So that will move the decimal point 3 places to the right.
So what do you get if you move the decimal in 4.25 three places to the right?
7(x+y) because their both factors of 7