Why are echinoderms found only in
marine environments?

Because its bodily functions only takes place in water.

Explanation:

Like many other organisms they do not move using any mascular system. Echinoderms has a unique type of water vascular system.They move feed and also breathe using this system.The system consists of hundreds of water filled tubes.And through this tubes the food is absorbed from the water and also their oxygen.Due to this they also move very slowly.Thats why they ar exclusively marine animals.

there are 35 white marbles

step-by-step explanation:

y- yellow marbles

4y + 5 = 45

subtract 5 from both sides

4y = 40

divide for from both sides

y = 10

plug in 10 to get 40 yellow marbles then subtract by 5 to get 35 marbles

thus there are only 10 yellow marbles