Answer:
Trevon scored -8.
Beth's score was 3/4 of trever's score = -8 *3/4 = -6
leah's score was 1/4 of beth's score. = -6 *1/4 = -1.5
Leah's score was -1.5
Answer:
Step-by-step explanation:
As an example, iodine-131 is a radioisotope with a half-life of 8 days. It decays by beta particle emission into xenon-131. After eight days have passed, half of the atoms of any sample of iodine-131 will have decayed, and the sample will now be 50% iodine-131 and 50% xenon-131.
50 grams to 25 grams is one half-life. 25 grams to 12.5 grams is another half-life. So, for 50 grams to decay to 12.5 grams, two half-lives, which would take 36 days total, would need to pass. This means each half-life for element X is 18 days.
This is a geometric sequence with common ratio (r) = 2.
an = ar^(n - 1)
a4 = a(2)^(4 - 1) = a(2)^3 = 8a
8a = 80
a = 80/8 = 10
7th term (a7) = 10(2)^(7 - 1) = 10(2^6) = 10(64) = 640
