Answer:
27.5 minutes
Step-by-step explanation:
Using,
R/R' = 2ᵃ/ᵇ------------------ Equation 1
From the equation,
R = mass of Element X before radioactive decay, R' = mass of element X after radioactive decay, a = Time taken, b = half life.
Given: R = 870 grams, R' = 154 grams, b = 11 minutes.
Substitute these values into equation 1
870/154 = 2ᵃ/¹¹
(870/154)¹¹ = 2ᵃ
Solve for a
2ᵃ = (5.649)¹¹
2ᵃ = 187061.26
Taking the logarithm of both side,
Log2ᵃ = Log(187061.26)
⇒ a = log(187061.26)/log2
a = 8.272/0.301
a = 27.5 minutes
x^2 - 7x + 15
_________________
(x+4)/ x^3 - 3x^2 - 13x + 78
- x^3 + 4x^2
----------------
- 7x^2 - 13x
- - 7x^2 - 28x
------------------
15x + 78
- 15x + 60
-------------
18
remainder = 18
Answer:
none of these have a solution of 2.
Step-by-step explanation:
4x+ 15 = 27
x=3
x + 6 =3
x = 3
2(x+5)=18
x = 4
x + 9 = 6
x = -3
if my understanding of what the equations are supposed to be please let me know what they are supposed to be, because with the way they are typed it is hard to tell :)
I think your answer is D) i am not 100% sure tho.
