Iroquois Algebra Blog: Unit 3 Test Prep Problems

Thursday, October 27, 2011

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.

4 comments:

AnonymousOctober 27, 2011 at 4:16 PM
Can we go over the area problems?
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Mrs. SkinnerOctober 27, 2011 at 5:04 PM
Nabeeha - refer to diagram I just inserted in the post, as well as the comments to the other post to see if they help. Are there specific quesitons that you have about area problems?
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Mrs. SkinnerOctober 27, 2011 at 5:49 PM
Equation for p.177 #3

(w+9)(w+2)-w(w+7) = 58 --> foil and don't forget that it is a -w not a +w to distribute.

(w+9)(w+2)-w(w+7) = 58
w^2+2w+9w+18-w^2-7w=58
4w+18=58
4w=40
w=10
w+7 = 17
w+2 = 12
w+9 = 19

Hope this helps some of you check your work in more detail!
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AnonymousOctober 27, 2011 at 6:17 PM
Re: p. 157 #48

Remember the laws of exponents: If you raise a power to a power, you multiply exponents. If you multiply powers, you add exponents.

Let's look at the first monomial in #48.
(2x^n)^3 The ^ is used to indicate an exponent.
The Power of a Product Law says to raise each factor in parentheses to the third power, so the thought step is . . .
(2)^3 (x^n)^3
The first factor simplifies to 8. For the second factor, you have a power of a power, so you multiply exponents, meaning you multiply n and 3.
The result is . . .
8x^3n That may look confusing, but remember that 3n is the exponent of x.

If you follow the same reasoning for (x^n)^5, you multiply exponents to get x^5n.

So after doing the exponentiation, you have . . .
(8x^3n)(x^5n).

You are now multiplying two monomials, so you multiply coefficients and add exponents. Adding 3n and 5n gives 8n.

Hence, the final answer is 8x^8n.
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