Which of the following must be true for an expression to be a difference of two squares? a. all variables are raised to an even power b. there are only two terms c. both terms have negative coefficients a. a, b, and mom b. b and c c. a and be d. a and

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:  

n+3

step-by-step explanation:

we are increasing our answer by 3 every time. we are moving from negatives to positives, which can make it look confusing, but we are indeed increasing by 3. our next to numbers would be 4, 7, and 10.