What two organ systems regulate other organ systems to maintain homeostasis, the maintenance of a
stable internal environment?

The Endocrine system and Nervous system

Explanation:

Homeostasis is the process of maintaining the internal environment of the body. The body regulates it's internal environment using the endocrine and nervous systems with various organs involved such as, lungs, kidneys, skin, pancreas. Temperature, blood sugar levels, oxygen and carbon iv oxide concentration, urea and other metabolic waste are examples of substances that the body needs to keep in control. The endocrine system is the system which are collection of glands that produce hormones needed for various regulatory purposes. This system consists of pituitary, thyroid, parathyroid, adrenal glands, pancreas. The nervous system responses to the various stimulus by causing the endocrine system to produce it's hormones for the appropriate response. For instance, when the level of water in the bloodstream becomes low, the hypothalamus (nervous system) in the brain release an hormone called antidiuretic hormone (ADH), the ADH stimulates th kidneys to absorb water through water channels and vice versa when there is excess water in the bloodstream.

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer