Using the pattern rule, find the missing value in the table.
y = x + 8
input X 1
output y 9
2 3 4
10 | 11 | [?]
Enter the number that belongs in the green box.
Enter

y=12

Step-by-step explanation:

y=x+8

9=1+8

10=2+8

and so in...

y=?

4+8=12

ending amount = beginning amount / (2^n)

where "n" = number of half-lives (or elapsed time / half-life)

ending amount = 50 mg / (2 ^10 / 5.3)

ending amount = 50 mg / (2 ^ 1.8867924528)

ending amount = 50 m / 3.6981210597

ending amount = 13.5203794557 mg

or about 13.5 mg remain

source: