Hardy-Weinberg equilibrium is not affected by which of the following factors?

Lesch-Nyhan disease is an $X$-linked recessive disorder that causes neurological damage in human beings. $A$ survey of $500$ males from a Caucasian population revealed that $20$ were affected with this disorder. What is the frequency of the normal allele in this population?

$A$ population is in Hardy-Weinberg equilibrium for a gene with only two alleles. If the gene frequency of an allele $A$ is $0.7$,the genotype frequency of $Aa$ is

In a random mating population,the frequency of the dominant allele is $0.7$. What will be the frequency of the recessive phenotype?

Explain the Hardy-Weinberg principle using an algebraic equation.