Step-by-step explanation:

Answer to the question
C. Lungs
Answer:
3
Step-by-step explanation:
3*3*3*3=81
that's my answer
Answer:
x = ± 
Step-by-step explanation:
9x² - 4 = 0 ( add 4 to both sides )
9x² = 4 ( divide both sides by 9 )
x² =
( take the square root of both sides )
x = ±
= ±
= ± 