Answer:
The 3.9 billion year old rock has undergone three half-lives (3.9 divided by 1.3 = 3). After 3 half-lives, 12.5% of the potassium-40 remains undecayed.
Explanation:
Answer:
2a and -5a
8 and -4
hahahah they are separate from each other
2a and -5a simplifies to -3a
8 and -4 simplifies to 4
Explanation:
hope this helps!