Question

Can you help with these two questions?

Answer 1

1) 155.91 grams would be left after 10 years

2) The population would be 376,478 in 2040

Step-by-step explanation:

The form of the exponential function is $y=a(b)^{x}$ , where

• a is the initial amount (y at x = 0)
• b is the growth/decay factor
• b = 1 + r, where r is the rate of growth
• b = 1 - r, where r is the rate of decay

1)

Scientists are studying a 500 grams sample of a radioactive element, which has an annual decay rate of 11%

∵ The initial amount is 500 grams

∴ a = 500

∵ The annual decay rate is 11%

∴ r = 11% = 11 ÷ 100 = 0.11

∵ b = 1 - r ⇒ decay

∴ b = 1 - 0.11 = 0.89

- We need to find how many grams of the sample would be left

  after 10 years

∴ x = 10

- Substitute all of these values in the form of the exponential function

∵ $y=500(0.89)^{10}$

∴ y = 155.9085996

- Round it to 2 decimal places

∴ y = 155.91

155.91 grams would be left after 10 years

2)

In 2000, the population of an Ohio town was 140,212. The population is expected to grow at a rate of 2.5% each year

∵ The population of an Ohio town was 140,212

∴ a = 140.212

∵ The population is expected to grow at a rate of 2.5% each year

∴ r = 2.5% = 2.5 ÷ 100 = 0.025

∵ b = 1 + r ⇒ growth

∴ b = 1 + 0.025 = 1.025

- We need to find the population in 2040

∵ The number of years is 2040 - 2000 = 40 years

∴ x = 40

- Substitute all of these values in the form of the exponential function

∵ $y=140212(1.025)^{40}$

∴ y = 376478.1709

- Round it to the nearest whole number

∴ y = 376,478

The population would be 376,478 in 2040

Learn more:

You can learn more about the functions in brainly.com/question/11921476

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