Need with finding half life or doubling time

12.2 hours

Step-by-step explanation:

You want to find t such that y = 2·y₀. That is, you want to solve

... 2y₀ = y₀·e^(0.0567t)

Dividing by y₀, you have

... 2 = e^(0.0567t)

and taking the natural log gives ..

... ln(2) = 0.0567t

... ln(2)/0.0567 = t ≈ 12.2248 . . . . divide by the coefficient of t

The doubling time is approximately 12.2 hours.

walter needs to make at least 5 more cookies but no more than 40. 5 ≤ x ≤ 40

step-by-step explanation:

20 ≤ x + 15 ≤ 55

subtract 15 from all parts

20-15 ≤ x + 15-15 ≤ 55-15

5 ≤ x ≤ 40

this means how many more cookies he has to make

walter needs to make at least 5 more cookies, but no more than 40 cookies; 5 ≤ x ≤ 40