What is the value of a in the equation , when ?

3
15
21
39

The value of a is 15

Step-by-step explanation:

Given the equation

we have to find the value of a when b is 3

Substitute b=3, we get

Hence, the value of a is 15

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)