Anyone know how to calculate the frequency of alleles? Please help!

Calculate frequency of homozygous recessive genotype. This is the only answer we know for certain.
tt = 5/26 = express as decimal = q2

Calculate frequency of t allele = sq root q2 = q = ?
Calculate Freq. of T allele (p) using p+q =1 = ?
Calculate Freq of Tt using 2pq = ?

Hardy-Weinberg Equilibrium is based on two equations:
p + q =1
p^2 + 2pq + q^2 = 1

p = frequency of dominant allele
q = frequency of recessive allele
p^2 = frequency of homozygote dominant
2pq = frequency of heterozygote
q^2 = frequency of homozygote recessive

All numbers are to four significant figures

tt is the homozygote recessive so q^2 = 5/26
q^2 = 0.1923
q = spareroot(0.1923) = 0.4385
p = 1 - 0.4385 = 0.5615
2pq = 2(0.4385)(0.5615) = 0.4924

Therefore the frequency of the t allele is 0.44
The frequency of the T allele is 0.56
The frequency of the Tt genotype is 0.49

You have now posted the same question 4 times (once with slightly different numbers). If you do not fully understand the answer I gave you please tell me what you would like me to clarify by posting a comment rather than repeatedly reposting the question.