The answer to this question is 'A low-pitched parent and a high-pitched parent have a child with a medium-pitched voice.'
Explanation:
If voice pitch is an inherited trait, than low-pitch + high-pitch parent equals a medium pitch. You can't have a child with a low or high-pitched voice.
F ( 18 ) = 1,50 * 18 + 12.50 = 27.00 + 12.50 = $39.50, x - number of movies. Answer: D ) $39.50; this is the amount Kelsey pays for 18 movies in 1 month