Answer:
the question is incomplete, so I looked for a similar one:
<em>After the release of radioactive material into the atmosphere from a nuclear power plant, the hay was contaminated by iodine 131 ( half-life, 8 days). If it is all right to feed the hay to cows when 10% of the iodine 131 remains, how long did the farmers need to wait to use this hay? </em>
iodine's half life (we are given x, we need to find b):
0.5A₀ = A₀eᵇˣ
x = 8 days
we eliminate A₀ from both sides
0.5 = eᵇ⁸
ln 0.5 = ln eᵇ⁸
-0.69315 = b8
b = -0.69315 / 8 = -0.08664
since the farmers need to wait until only 10% of the iodine remains (we already calculated b, now we need to find x):
0.1A₀ = A₀eᵇˣ
0.1 = eᵇˣ
ln 0.1 = bx
where b = -0.08664
x = ln 0.1 / -0.08664 = -2.302585 / -0.08664 = 26.58 days
1 to 100 of Prime Numbers
2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97.
The number 15 has divisors of 1,3,5,15 because:
15/1=15
15/3=5
15/5=3
15/15=1
So 15 is not a prime number.
The number 13 has only two divisors of 1,13.
13/1=13
13/13=1
So 13 is a prime number.
Answer:
Your answer is c hope this helps
Answer:
If we do square on both sides we get two answers i.e. (x+12)^2=(3x+20)^2
(x^2)+24x+144=(9x^2)+120x+400
(8x^2)+96x+256=0
(x^2)+12x+32=0
(x+4)(x+8)=0
x= -4 or x= -8.
Else we have another method
x+12=3x+20
x+12–20=3x
x-8=3x,
Now square on both sides.
(x-8)^2=(3x)^2
x^2–16x+64=(9x^2)
(9x^2)-(x^2)+16x-64=0
(8x^2)+16x-64=0
(x^2)+2x-8=0
(x+4)(x-2)=0
x= -4 or x= 2.
But It Didn’t Satisfy for The Equation When
x=2 or x= -8,So The Value of x will be -4 which satisfies given question.
