How to erite a sequence of 1/4 , 1/2,3 write a rule for the sequence 1/4 1/2 3/4

The equation for finding the equation of an arithmetic sequence is an=a1+(n-1)d, where n is the input for the sequence, a1 is the first term, and d is the difference between each term. 

a1= 1/4
d= 1/4 

an= 1/4 + (n-1)(1/2) - First you need to distribute the 1/2 to both the n and -1 to get:    an= 1/4 + 1/2n -1/2.

Then you need to add like terms (1/4-1/2) to get an=1/2n-1/4.  Hope this helps!

She should use 12/3 to measure