Which expression fits this description??

Step-by-step explanation:

We can immediately assume that the answer is either the first or third one based off of the second statement. A product is the result of multiplication, and if you see a number and letter together like in the first and third answers, it means they are to be multiplied. For example, 2a = 2 x a. With the first statement, there are 2 terms in all of the equations so that's no help, but the word sum is the result of addition. In which all two terms are added, so . . . also no help. :( Now the last statement. The thing that will conclude all of your questions. A quotient is the result of division, and it's supposed to be between b and 4. As we can see, in the third equation, they subtract b and 4. That's not division! So that leaves us with one answer. The first equation. . .

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)