What would make a conversion not possible? Related to dimensional analysis

Tod does not have any cookies. david gives jeff 8 cookies. then he splits half of the cookies he has left with tod. david let’s c represent the number of cookies that he starts with. he finds the number of cookies that tod has is 1/2 the difference of c and 8. write an expression to represent the number of cookies that tod has.

Solve the equation below: (x+4)/6x=1/x a. x=2 b. x=0,2 c. x=-2 d. x=0,-2

The length of a rectangular piece of land is 92 yards more than three times its width. the perimeter is 760 yards. find its dimensions.