You have 32 grams of a radioactive kind of gold. if its half-life is 3 days, how much will be left after 6 days?

a. 5 grams
b. 4 grams
c. 16 grams
d. 8 grams

d. 8 grams.

Step-by-step explanation:

After 1 half life there is 1/2 * 32 = 16 grams left , after another half-life ( at 6 days) there is 1/2 * 16 = 8 grams left.

me

step-by-step explanation:

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15