Exponential Equations and Logarithm

Solve the exponential equation 4^(x) = 100 using logarithms.

• x = 3.32

• x = 3.51

• x = 3.78

• x = 3.05

A population of bacteria increases by 70% each hour. If there are initially 100 bacteria, how many will there be after 9 hours?

• 11859

• 12746

• 13956

• 14251

A radioactive substance decays by 20% each day. If there are initially 500 grams of the substance, how much will be left after 5 days?

• 163.84 grams

• 250.13 grams

• 75.24 grams

• 100 grams

A population of rabbits increases by 20% every year. If there are initially 50 rabbits, make an equation to find the rabbit population.

• y=50*20^x

• y=20*50^x

• y=50*1.2^x

• y=50+1.20x

A radioactive substance decays by 10% each week. If there are initially 1000 grams of the substance, how much will be left after 4 weeks?

• 300 grams

• 500 grams

• 656.1 grams

• 800 grams

Convert the exponential equation 7^5 = 16807 to logarithmic form.

• log7(5) = 16807

• log16807(7) = 5

• log5(16807) = 7

• log7(16807) = 5

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