Find the perimeter of the rectangle whose coordinates are A (5, 3), B (8, 3), C (8,5), and D (5,5).

O 10 units
O 12 units
O 9 units
O 8 units

this is false ^.^ lol

a_n = a_1 + (n - 1)d

the first term is 6.

the common difference d = ?

when you find d, replace n with 7 and d with the common difference to find your answer.

answer is 8 r5

step-by-step explanation:

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: