Math Core

Unit 7 · Test

Unit 7 test: Exponents and Exponential Functions

15 questions. Answer them all, then submit to see your score. Solutions unlock after you submit.

This test covers all of the Exponents unit: properties of exponents, zero and negative exponents, radicals and rational exponents, exponential functions, exponential growth and decay, and geometric sequences.

Question 1

Write x5⋅x8x^5 \cdot x^8 as a single power xnx^n. What is nn?

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 2

Simplify (3x4)2(3x^4)^2.

Question 3

Write (a3)4a6\dfrac{(a^3)^4}{a^6} as a single power ana^n. What is nn?

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 4

Evaluate 6−26^{-2}.

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 5

Simplify x−2y3x3y−1\dfrac{x^{-2} y^3}{x^3 y^{-1}} and write it with positive exponents.

Question 6

Evaluate 642/364^{2/3}.

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 7

Write 50\sqrt{50} in simplest form as a2a\sqrt{2}. What is aa?

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 8

Let f(x)=5⋅2xf(x) = 5 \cdot 2^x. Find f(3)f(3).

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 9

Which function shows exponential decay?

Question 10

Which table could represent an exponential function?

Question 11

You invest $1,500 at 5%5\% interest compounded annually. How much is the investment worth after 44 years? Round to the nearest cent.

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 12

A 120120-gram sample has a half-life of 1010 years. How many grams remain after 3030 years?

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 13

A car's value is modeled by V=24000(0.93)tV = 24000(0.93)^t, where tt is in years. By what percent does the value decrease each year?

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 14

Find the 1010th term of the geometric sequence 3,6,12,24,…3, 6, 12, 24, \dots

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 15

A geometric sequence has a1=81a_1 = 81 and r=−13r = -\tfrac{1}{3}. Find a5a_5.

Enter a number. Fractions like 3/4 and sqrt(2) are OK.