After the release of radioactive material into the atmosphere from a
nuclear power plant the hay in that country was contaminated by a
radioactive isotope (half-life 88 days). if it is safe to feed the hay
to cows when 15% of the radioactive isotope remains, how long
did the farmers need to wait to use this hay? round to the nearest
day.

$15 each

step-by-step explanation:

$45/3 children= $15 each

sorry i just need to anwers this to get points

step-by-step explanation:

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places