How many zeroes do we write when we write all the integers 1 to 243 in base 3?

Ill mark the brainliest if you me with the these three questions 7,8,9

2.5 milligrams is equivalent to how many grams

Factor the polynomial, if possible. if the polynomial cannot be factored, write prime. 9n^3 + 27n^2 – 25n – 75