Answer:
33 cards
Step-by-step explanation:
3 cards already. 5 in 1 hour = 5 x 6 hours = 30 cards + 3 cards
33 cards
Answer:
25 + 14
Step-by-step explanation:
Sum means addition of values.
Answer:
what grade are you in? because I do not know what is this
Step-by-step explanation:
Answer: 400 520<15x+400x 15x+400>520
Step-by-step explanation:
From the statement you can find the function that represents the percent of strontium-90 that remains after t years of the nuclear accident.
Call P the percent:
---> P = e ^ (- 0.025t)
Now you can also estimate the half-life of the isotope strontium-90:
Call Pi the initial percent and P2 the half percent:
P2 = 0.5 * P initial =>
P2 = 0.5 * Pinitial = Pinitial * e ^ (-0.025 t)
=> 0.5 = e ^ (-0.025t)
=> ln 0.5 = -0.025t
=> t = - ln (0.5) / 0.025
=> t = 27.7 years <----- half-time