D.8
A and C are out because they would get you ether lower or equal to 20, which is equal to AC and your trying to find X in AB which is so posed to be the what equals AC+BC.
AB=AC+BC
5x=20+BC
5(8)=20+BC
40=20+BC
40=20+20
AC equals 20. AB will have to equal AC+ CB. If you put in A.4 in AB 5X you will get twenty and that not what you want. You want to get a number that will get you the an answer greater to AC. So 5(8)=40.
Let's see what we can get by dividing 625 by 5, as it ends with a 5:
625/5 = 125
So we have 5 as one of our factors. Let's divide again by 5:
125/5 = 25
Our current prime factors now are 5 and 5, but we aren't finished. Divide again by 5:
25/5 = 5
Now we know that the prime factorization of 625 is 5 * 5 * 5 * 5, which can also be shown as 5⁴.
Answer:
There will be 48 neutrons.
Step-by-step explanation:
Hope this helps and have a great day :)