Having no dimples is a recessive trait in humans that is controlled by a single gene. how many recessive alleles must a person have to have no dimples ?

the answer your looking for on apex is 2

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.

: -)

thats not even an aswer choice