How can a poly genic trait be easily identified

The presence of the polygenic trait masks the other possible alleles involved. There are only two possible phenotypes for the trait. The graphing of the possible phenotypes results in a bell curve. Usually, traits are polygenic when there is wide variation in the trait. For example, humans can be many different sizes. Height is a polygenic trait, controlled by at least three genes with six alleles. If you are dominant for all of the alleles for height, then you will be very tall.

Explanation:

try using substitution:

x + y - 6 = x - y. (i'm not giving you the exact answer). since 0 = x - y, then sub 0 in the equation with x - y. combine your like terms, and then use inverse operations, and you'll have your answer.

: -)