When dividing by a decimal, why can you multiply the divisor and dividend by the same power of ten?

Asequence is defined recursively by the formula  f(n  +  1)  =  f(n)  +  3 . the first term of the sequence is  –4. what is the next term in the sequence? –7–117

3. a sum of $2700 is to be given in the form of 63 prizes. if the prize is of either $100 or $25, find the number of prizes of each type.

Gabrielle's age is two times mikhail's age. the sum of their ages is 84. what is mikhail's age?