The sum of the square root of a number and six

Ineed if you could explain and give me the answer you! this needs done

The following division is being performed using multiplication by the reciprocal find the missing numbers is 5/12 divided by x/3 equals 5/12 times x/10 equals 1/x

Ateacher brought a pack of 17 batteries . each calculator uses 3 batteries . how many calculator can the teacher fill with batteries