9 is a rational number because it can be expressed as the quotient of two integers: 9 ÷ 1.
26 is not a perfect square because the square root of 26 is 5.09,but I think and I guess 25 is a perfect square instead of 26......
Answer:
The explicit rule is:
Step-by-step explanation:
The explicit rule is given by:

The given sequence is 25,21,17,13

d=21-25
d=-4
We plug in the values into the formula to get;


