Writing Exponential Functions

Which exponential equation passes through (0,7) and (1,21)?

• $y=3\cdot7^x$

• $y=3\left(\frac{1}{7}\right)^x$

• $y=7\cdot3^x$

• $y=7\left(\frac{1}{3}\right)^x$

Tags

CCSS.HSA.CED.A.2

CCSS.HSF.BF.A.1

CCSS.HSF.LE.A.1

CCSS.HSF.LE.A.2

Which exponential function matches the table?

• $y=25\cdot5^x$

• $y=125\cdot5^x$

• $y=25\left(\frac{1}{5}\right)^x$

• $y=125\left(\frac{1}{5}\right)^x$

Tags

CCSS.HSF.IF.B.4

CCSS.HSF.LE.A.1

CCSS.HSF.LE.A.2

Which exponential function matches the graph?

• $y=8\cdot2^x$

• $y=8\left(\frac{1}{2}\right)^x$

• $y=2\cdot8^x$

• $y=2\left(\frac{1}{8}\right)^x$

Tags

CCSS.HSF.IF.B.4

CCSS.HSF.LE.A.1

CCSS.HSF.LE.A.2

A colony of bacteria starts with 5 individuals and doubles each hour. Which exponential function models the number of bacteria, b, after t hours?

• $y=2\cdot5^x$

• $y=5\cdot2^x$

• $b=2\cdot5^t$

• $b=5\cdot2^t$

Tags

CCSS.HSA.CED.A.1

CCSS.HSA.SSE.A.1

CCSS.HSF.BF.A.1

CCSS.HSF.LE.A.1

CCSS.HSF.LE.A.2

CCSS.HSF.LE.B.5

You deposit $4,000 into a savings account that gains 2% annual interest. Which exponential equation shows the account balance, b, after t years?

• $b=4000\left(1.2\right)^t$

• $b=4000\left(0.8\right)^t$

• $b=4000\left(1.02\right)^t$

• $b=4000\left(0.98\right)^t$

Tags

CCSS.HSA.CED.A.1

CCSS.HSA.SSE.A.1

CCSS.HSF.BF.A.1

CCSS.HSF.LE.A.1

CCSS.HSF.LE.A.2

An elk population starts with 300 individuals and decreases by 6% each year. Which function models the elk population, p, after t years?

• $p=300\left(1.6\right)^t$

• $p=300\left(1.06\right)^t$

• $p=300\left(0.4\right)^t$

• $p=300\left(0.94\right)^t$

Tags

CCSS.HSF.BF.A.1

CCSS.HSF.LE.A.1

CCSS.HSF.LE.A.2

CCSS.HSF.LE.B.5

A squirrel population starts with 40 individuals and increases by 18% each year. Estimate the number of squirrels after 5 years. Round to the nearest whole.

Tags

CCSS.HSA.CED.A.1

CCSS.HSA.SSE.A.1

CCSS.HSF.BF.A.1

CCSS.HSF.BF.A.2

CCSS.HSF.LE.A.1

CCSS.HSF.LE.A.2

A new truck costs $55,000 and the value depreciates by 11% each year. Estimate the value of the truck after 4 years. Round to the nearest dollar.

Tags

CCSS.HSA.SSE.A.1

CCSS.HSF.BF.A.1

CCSS.HSF.LE.A.1

CCSS.HSF.LE.A.2

CCSS.HSF.LE.B.5