Answer: the 1st one.
Step-by-step explanation: becuase today I was helping out a freind with this. So it the first one
N² - 49 = 0
<u> + 49 + 49</u>
n² = 49
n = <u>+</u>7
The solution to the problem is {7, -7}.
Answer:
-4 and 4
Step-by-step explanation:
Have a good day.
Answer:
16.07 milligrams
Step-by-step explanation:
From the question,
Using the formula of radioactive decay,
R/R' = 2ᵃ/ᵇ..................... Equation 1
Where R = Original mass of the polonium-210, R' = Final mass of polonium-210 after decaying, a = Total disintegration time, b = half life of polonium-210.
Make R' the subject of the equation
R' = R/(2ᵃ/ᵇ)................ Equation 2
Given: R = 100 milligrams, a = 1 years = 365 days, b = 138.39 days
Substitute these values into equation 2
R' = 100/(2³⁶⁵⁰⁰/¹³⁸³⁹)
R' = 100/(6.222)
R' = 16.07 milligrams of plonium-210
