The total frequency of the red allele and the white allele in decimals or fraction adds up to 1. Here the frequency of red allele(cr) is p=0.7 and we need to determine the frequency of white allele (cw) which is q in the population.

The punnett square shows the probability of each genotype and corresponding phenotype.
The white allele has genotype : cw
The red allele has genotype : cr
The punnett square cross is as below:-
according to Hardy Wienberg equilibrium:

The phenotype of offspring will be 0.49 red flowers, 0.42 pink flowers and 0.09 red flowers.