Answer:
ok well I usually just add 105, 5 times and I get the answer.
Explanation:
105 + 105= 210
210 + 105= 315
315+ 105= 420
420 + 105 = 525
The answer is 525
There is another way to do it ok soo if we multiply 100 x 5 = 500
and 5 x 5 equals 25 and then we add them together we get 525