Please help me, I don't understand this

4, based on the assumption that the R allele is dominant over the r allele, and that the T allele is dominant over the t allele.

Explanation:

Any bush with a dominant petal color allele (R) will have red petals. This includes Rr and RR.

Any bush with a dominant bush size allele (T) will have a tall bush. This includes Tt and TT.

The only way to acquire a short bush or pink petals is to have two recessive alleles together (tt, rr).

RRTT, RrTT, RRTt, and RrTt -> red petals with tall bushes

RRtt, Rrtt -> Red petals with short bushes

rrTt, rrTT -> pink petals and tall bushes

rrtt-> pink petals with short bushes.

These are the four phenotype variations possible in this dihybrid cross.

multiplying and dividing the two decimals and the eqations by the same number of the overalls