Unit 3 Test Prep Problems - Answer Key

Here are the answers to Unit 3 review problems assigned in the previous post. Please check your answers and, if you have a question, send a comment to THIS post. Mrs. Skinner or Mr. Roeser will respond. This review session is open from now until 9:00 PM this evening. Please remember that you should also be consulting your study guide, as there are topics on the guide that are not covered by this problem set. Thanks for participating in this online review.

p. 148 Oral Exercises

#2 -st² and 3t²s; 2s²t and –s²t

Like terms are terms that have the same variable(s) and exponent(s).

#5 degree 8 (Add the exponents of all the variables.)

#7 degree 3

#9 degree 6

#12 -4x³ – 2x² + 6x – 5; cubic four-term polynomial

#14 p²q³ – 3pq⁴; degree 5 binomial

#16 -s²t² + 2s²t + 3st²; quartic trinomial

p. 149 Written Exercises

#43 2a³ + 2ab² + b³

pp. 153-154 Written Exercises

#20 -3r³s⁶

#34 0

To multiply monomials, multiply the coefficients, keep the same base, and add the exponents.

p. 157 Written Exercises

#16 16t¹⁶

#28 10x⁹y⁷

#48 8x⁸ⁿ

pp. 159-160 Written Exercises

#17 2x⁴ – 3x³y – x²y²

#40 Area = 2x² + 5x units²

pp. 162-163 Written Exercises

#16 10k² – 11k – 6

#34 -2a³ – 5a² + 11a - 4

p. 177 Self-Test 3

#3 The dimensions of the pond are 17 ft by 10 ft.

Unit 3 Test Prep Problems

Below are some problems from your textbook that you can work to prepare for the Unit 3 test. Answers will be posted on this blog at 7:00 PM on Thursday, October 27. Ms. Skinner and Mr. Roeser will be available from 7:00 to 9:00 PM to respond to questions that you may have. Send your questions as a comment to the post with the answer key, not as an e-mail. THIS PROBLEM SET IS NOT A SUBSTITUTE FOR THE STUDY GUIDE. THERE ARE ITEMS ON THE STUDY GUIDE THAT ARE NOT COVERED HERE.

p. 148 Oral Exercises

#2 – The textbook uses “similar monomials” to mean like terms.

In addition to naming the like terms, tell how you know which terms are like terms (go back to the definition of like terms).

#5, 7, 9 – Just state the degree of the entire monomial.

#12, 14, 16 – Rewrite in standard form, if necessary. Then classify each polynomial by degree and number of terms using vocabulary, not numbers.

p. 149 Written Exercises

#43 – Be sure your answer is in standard form.

pp. 153-154 Written Exercises

#20, 34

Also, state the rule for multiplying monomials.

p. 157 Written Exercises

#16, 28, 48

Yes, #48 is a little tougher, but just apply the same Multiplication Laws of Exponents that you used for the first two exercises in this set.

pp. 159-160 Written Exercises

#17, 40

pp. 162-163 Written Exercises

#16, 34 – Again, write answers in standard form

p. 177 Self-Test 3

#3 – Show all four steps as instructed.

Word Problem Practice

D=rt Problem:

Bill started biking from his home at 8:00AM at a rate of 16km/h.  His sister Julie started biking from the same house at 8:30AM at a rate of 20km/h.  If they are traveling along the same route, how long is it before Julie overtakes her brother?

HINT (They are heading in the same direction and will travel the same distance!)

CHART:

                  km/h              h                   km

   Bill           16              x + 0.5         16(x+0.5)

   Julie          20                 x                 20x

Equation:  16(x+0.5) = 20x

                   16x +8 = 20x

                           8 = 4x

                            2 = x   <--  Julie's time riding

                         2.5 = x + 0.5  <-- Bill's time riding

Check:

    2h(20km/h) = 40km

    2.5h(16km/h) = 40km

It will take Julie 2 hours to over take Bill on the bike ride.

Be sure to check back later as I will post more problems to help you study!