41. Suppose a laboratory has a 60 g sample of polonium-210. The half-life of polonium-210 is about 138 days. a. How many half-lives of polonium-210 occur in 828 days?
b. How much polonium is in the sample 828 days later?
a. 6; 0.94 g
c. 6; 10 g
b. 7;0.47 g
d. 6; 4,140 g
ettings

b

Step-by-step explanation:

answer: get more recipes with 3 magazines for $20! i often use chicken broth instead of water. 3 tablespoons butter, divided; 1/2 cup freshly grated parmigiano-reggiano bring water and salt to a boil in a large saucepan; pour polenta slowly into 5 minutes to thicken; stir and taste for salt before transferring to a serving bowl.

{x = -1/2 ,   y = -1

step-by-step explanation:

solve the following system:

{2 x + y = -2

{10 x - 3 y = -2

in the first equation, look to solve for y:

{2 x + y = -2

{10 x - 3 y = -2

subtract 2 x from both sides:

{y = -2 x - 2

{10 x - 3 y = -2

substitute y = -2 x - 2 into the second equation:

{y = -2 x - 2

{10 x - 3 (-2 x - 2) = -2

10 x - 3 (-2 x - 2) = (6 x + 6) + 10 x = 16 x + 6:

{y = -2 x - 2

{16 x + 6 = -2

in the second equation, look to solve for x:

{y = -2 x - 2

{16 x + 6 = -2

subtract 6 from both sides:

{y = -2 x - 2

{16 x = -8

divide both sides by 16:

{y = -2 x - 2

{x = -1/2

substitute x = -1/2 into the first equation:

{y = -1

{x = -1/2

collect results in alphabetical order:

answer:   {x = -1/2 ,   y = -1