A40 gram sample of a substance that's used for drug research has a k-value of 0.1446. find the substance's half life in days

The applicable decay formula is:N = No*e^(-kt)WhereN = Mass left after time tNo = Original massk = constantt = half lifeUsing the values given,N/No = e^(-0.1446t) = 1/2ln (1/2) = -0.1446 t *ln e^1-0.6931 = -0.1446 tt = 0.6331/0.1446 = 4.79 daysTherefore, half-life is 4.8 days.

c. 27 units.

step-by-step explanation:

we are told that in circle a, ∠bae ≅ ∠dae.

we can see from our given diagram that in and ;

, as these are radii of our given circle.

therefore, by sas congruence postulate.

hence, side be will be equal to side de as corresponding parts of congruent triangles are congruent. so we can set an equation to find the value of x as:

now let us substitute x=17 in the expression for the length of be.

therefore, length of be will be 27 units and option c is the correct choice.