How can we use exponents to represent powers of ten

Which is an equation for the nth terms of the sequence 12,15,18,21

How many grams must be adde to 970g to make 1 and a half kg

Correct answer brainliest asap an d 99 pointsss what are relative frequencies to the nearest hundredth of the columns of two way table column a 102, 18 colunm b 34, 14 answers choices 0.15 0.25 0.29 0.44 0.56 0.71 0.75 0.85