Question

400 written as a product of its prime factors is 2 x 2 x 2 x 2 x 5 x 5.

Answer 1

800/2
400/2
200/2
100/2
50/2
25/5
5/5

2x2x2x2x2x5x5
Simplify
2^5x5^2

Basically divide by the smallest prime number possible until you get to the number 1

Answer 2

Answer:  2 x 2 x 2 x 2 x 2 x 5 x 5

Explanation:

We start with the string 2 x 2 x 2 x 2 x 5 x 5

Then we tack on a "2 x" up front, or at the very left, so that we double the result. This is because the jump from 400 to 800 is "times 2".

So we go from 2 x 2 x 2 x 2 x 5 x 5 to 2 x 2 x 2 x 2 x 2 x 5 x 5

We can condense this into $2^5*5^2$