We know that
<span>This problem can be represented through the following equation
</span>
A = A₀(1/2)^t/h
where
A-----------> is the amount of substance left after time t
A₀ ----------> is the original amount---------> 2 g
h-------------> is the half-life-----------> 8 days
for A=0.04 g
t=?
0.04 = 2(1/2)^t/8
0.02 = (1/2)^t/8
Take ln on both sides:
ln(0.02) = ln [(1/2)^t/8]
ln(0.02) = (t/8)(ln 1/2)
t = 8*ln(0.02)/ln(1/2)
t = 45.15 days
the answer is 45.15 days
Answer:
![\boxed{ \sf{1. \: \: \: \: 46.67}}](https://tex.z-dn.net/?f=%20%5Cboxed%7B%20%5Csf%7B1.%20%5C%3A%20%20%5C%3A%20%20%5C%3A%20%20%5C%3A%2046.67%7D%7D)
![\boxed{ \sf{2. \: \: \: \: 41.67\%}}](https://tex.z-dn.net/?f=%20%5Cboxed%7B%20%5Csf%7B2.%20%5C%3A%20%20%5C%3A%20%20%5C%3A%20%20%5C%3A%2041.67%5C%25%7D%7D)
![\boxed{ \sf{3. \: \: \: \: 0.375}}](https://tex.z-dn.net/?f=%20%5Cboxed%7B%20%5Csf%7B3.%20%5C%3A%20%20%5C%3A%20%20%5C%3A%20%20%5C%3A%200.375%7D%7D)
![\boxed{ \sf{4. \: \: \: \: 120}}](https://tex.z-dn.net/?f=%20%5Cboxed%7B%20%5Csf%7B4.%20%5C%3A%20%20%5C%3A%20%20%5C%3A%20%20%5C%3A%20120%7D%7D)
Step-by-step explanation:
1. Let the number be x
![\sf{15\% \: of \: x = 7}](https://tex.z-dn.net/?f=%20%5Csf%7B15%5C%25%20%5C%3A%20of%20%5C%3A%20x%20%3D%207%7D)
![\dashrightarrow{ \sf{ \frac{15}{100}x = 7}}](https://tex.z-dn.net/?f=%20%5Cdashrightarrow%7B%20%5Csf%7B%20%5Cfrac%7B15%7D%7B100%7Dx%20%3D%207%7D%7D%20)
![\dashrightarrow{ \sf{0.15x = 7}}](https://tex.z-dn.net/?f=%20%5Cdashrightarrow%7B%20%5Csf%7B0.15x%20%3D%207%7D%7D)
![\dashrightarrow{ \sf{x = \frac{7}{0.15}}}](https://tex.z-dn.net/?f=%20%5Cdashrightarrow%7B%20%5Csf%7Bx%20%3D%20%20%5Cfrac%7B7%7D%7B0.15%7D%7D%7D)
![\dashrightarrow{ \sf{46.67}}](https://tex.z-dn.net/?f=%20%5Cdashrightarrow%7B%20%5Csf%7B46.67%7D%7D)
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2. Let the percent be x %
![\sf{x\% \: of \: 60 = 25}](https://tex.z-dn.net/?f=%20%5Csf%7Bx%5C%25%20%5C%3A%20of%20%5C%3A%2060%20%3D%2025%7D)
![\dashrightarrow{ \sf{ \frac{x}{100} \times 60 = 25}}](https://tex.z-dn.net/?f=%20%5Cdashrightarrow%7B%20%5Csf%7B%20%5Cfrac%7Bx%7D%7B100%7D%20%20%5Ctimes%2060%20%3D%2025%7D%7D)
![\dashrightarrow{ \sf{ \frac{60}{100}x = 25}}](https://tex.z-dn.net/?f=%20%5Cdashrightarrow%7B%20%5Csf%7B%20%5Cfrac%7B60%7D%7B100%7Dx%20%3D%2025%7D%7D%20)
![\dashrightarrow{ \sf{0.6x = 25}}](https://tex.z-dn.net/?f=%20%5Cdashrightarrow%7B%20%5Csf%7B0.6x%20%3D%2025%7D%7D)
![\dashrightarrow{ \sf{x = \frac{25}{0.6} }}](https://tex.z-dn.net/?f=%20%5Cdashrightarrow%7B%20%5Csf%7Bx%20%3D%20%20%5Cfrac%7B25%7D%7B0.6%7D%20%7D%7D)
![\dashrightarrow{ \sf{41.67\%}}](https://tex.z-dn.net/?f=%20%5Cdashrightarrow%7B%20%5Csf%7B41.67%5C%25%7D%7D)
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3. ![\sf{0.15\% \: of \: 250}](https://tex.z-dn.net/?f=%20%5Csf%7B0.15%5C%25%20%5C%3A%20of%20%5C%3A%20250%7D)
![\dashrightarrow{ \sf{ \frac{0.15}{100} \times 250}}](https://tex.z-dn.net/?f=%20%5Cdashrightarrow%7B%20%5Csf%7B%20%5Cfrac%7B0.15%7D%7B100%7D%20%20%5Ctimes%20250%7D%7D)
![\dashrightarrow{ \sf{0.375}}](https://tex.z-dn.net/?f=%20%5Cdashrightarrow%7B%20%5Csf%7B0.375%7D%7D)
----------------------------------------------------------
4. Let the number be x
![\sf{250\% \: of \: x = 300}](https://tex.z-dn.net/?f=%20%5Csf%7B250%5C%25%20%5C%3A%20of%20%5C%3A%20x%20%3D%20300%7D)
![\dashrightarrow{ \sf{ \frac{250}{100} \times x = 300}}](https://tex.z-dn.net/?f=%20%5Cdashrightarrow%7B%20%5Csf%7B%20%5Cfrac%7B250%7D%7B100%7D%20%20%5Ctimes%20x%20%3D%20300%7D%7D)
![\dashrightarrow{ \sf{2.5x = 300}}](https://tex.z-dn.net/?f=%20%5Cdashrightarrow%7B%20%5Csf%7B2.5x%20%3D%20300%7D%7D)
![\dashrightarrow{ \sf{x = \frac{300}{2.5} }}](https://tex.z-dn.net/?f=%20%5Cdashrightarrow%7B%20%5Csf%7Bx%20%3D%20%20%5Cfrac%7B300%7D%7B2.5%7D%20%7D%7D)
![\dashrightarrow{ \sf{x = 120}}](https://tex.z-dn.net/?f=%20%5Cdashrightarrow%7B%20%5Csf%7Bx%20%3D%20120%7D%7D)
Hope I helped!
Best regards! :D
Answer:
D. y = 6x – 5
Step-by-step explanation:
Red: 6x – 2y = 10
Blue y = 6x – 5
Answer:
B its a guess because nothing is shown
Step-by-step explanation:
Answer:
I believe it would be 1
Step-by-step explanation: