Answer:
4/9
Step-by-step explanation:
I think it's D but make it sire
Answer:
A. 2.8 billion years old
Step-by-step explanation:
1/16 = (1/2)^4, so 4 half-lives have elapsed.
4 · 0.700 billion years = 2.8 billion years
The rock is 2.8 billion years old.
2x²-5x-3 = 0
(2x+1) (x-3) = 0
2x+1 = 0
2x = -1
x = -½
x-3 = 0
x = 3
then x = -½ , x= 3
