## Corrections

Early printings of the course guide did not include sample responses for each modeling prompt. To access these, visit the modeling prompt pages online (link).

In the Course Guide, under Scope and Sequence, the Pacing Guide for Algebra 1 Unit 4 was edited to indicate that none of the lessons in that unit are optional.

Unit 1, Lesson 3, Cool-down. In the solution, changed Q1 to 40.

Unit 1, Lesson 16, Practice Problems 4 and 5. The solutions used median to compute boundary values for outliers. The statements and solutions are updated to include values for quartiles and use them in the solution explanations.

Unit 2, Lesson 1, Practice Problem 3. The solution fractions were inverted. The correct answer is \(\frac{C}{20}\).

Unit 2, Lesson 3, Practice Problems 3, 4, and 9. The solution for problem 3 is \(t = 48c\). The solution for problem 4 is \(32b = q\). The solution to problem 9 part a is \(D = \frac{500}{40}\).

Unit 2, Lesson 5, Cool-down. The third question referred to "teaspoons" instead of "tablespoons." This has been corrected.

Unit 2, Lesson 8, Practice problem 10. The last line of Han's solution changed to \(6 = 5\). The responses for C and D changed to \(x = 6\) and \(x = 5\) respectively.

Unit 2, Lesson 9, Activity 3. The responses for questions 1 and 2 now correctly uses 36,000 for the average worker salary.

Unit 2, Lesson 15, Lesson synthesis. For the second discussion question, changed the coordinate pair to \((2,3)\).

Unit 2, Lesson 18, Practice problem 4. In the solution, changed \(w \ge 12\) to \(w \ge 36\).

Unit 2, Lesson 18, Practice problem 8. The solution is choice C.

Unit 2, Lesson 19, Activity 3. The solutions for questions 2 and 3 were opposite of their correct solutions. The hotel pays better for fewer hours. Graph B goes with Inequality 1.

Unit 2, Lesson 19, Practice Problem 7. The first question now defines \(q\) as the number of quarters instead of defining \(d\) for the number of dimes.

Unit 2, Lesson 20, Activity 20.4. The solution to 3 is now correct as \(x \leq 2\) and the number line for choice B is updated to reflect this. The solution to 6 is now correct as \(x \geq 2\) and the number line for choice C is updated to reflect this.

Unit 2, Lesson 21, Activity 2. In the activity synthesis, the graph for \(\text{-}2 \geq \text{-}4\) has been updated to show the boundary at \(y = 2\).

Unit 2, Lesson 21, Practice Problem 3. The solution to the first part should read, "Sample responses: \((5,10), (\frac13,3), (\text-3,\text-2)\)."

Unit 2, Lesson 22, Activity 3. The solution to 1b is updated to a combination of items that makes more than \$100.

Unit 2, Lesson 22, Activity 4. The solutions to 4b and 4c are updated. 4b is 1,600 tickets and 16 concerts. 4c is 2,500 tickets and 10 concerts.

Unit 2, Lesson 22, Practice Problem 4. Changed the solution to the second part: "See graph. A solution represents a number of dimes and a number of quarters that together are worth $8.50 or more."

Unit 2, Lesson 23, Activity 2. The solution for Advertising Packages part 2d was incorrect. It has been corrected to, "The agency needs to sell more than 35 basic packages."

Unit 2, Lesson 23, Practice Problem 9. Changed the first sentence of the solution to "\((1.5,\text-4)\) is a solution but \((4,\text-4)\) is not a solution."

Uniy 2, Lesson 26, Practice Problem 1. The solution for the first question now correctly uses \$16 instead of \$18.

Unit 2, Lesson 26, Practice Problem 3. The first inequality is now given as strictly greater than and the second inequality uses less than or equal to.

Unit 2, Lesson 26, Practice Problem 4. Changed order of answer choices so that the solution is correct.

- \(2x-5y\ge20\)
- \(5x+2y\ge20\)
- \(4x-10y\le20\)
- \(4x-5y\ge20\)
- \(2x+10y\le20\)

Unit 3, Lesson 1, Activity 3. The response for question 2 is corrected to 10%.

Unit 3, Lesson 1, Practice Problem 1. The total for the grade 8 row is corrected to 39.

Unit 3, Lesson 2, Activity 2. The sample response for question 1 now correctly uses \(\frac{54}{96}\) to get 56%.

Unit 3, Lesson 4, Activity 2. The solution for question 6 is 10.6 kilograms because \(2.6 + 40 \boldcdot 0.2 = 10.6\).

Unit 3, Lesson 6, Activity 3. The points for graph L were reflected over the \(x\)-axis. The blackline master has been corrected.

Unit 3, Lesson 7, Activity 2. Graph J in the synthesis is updated to have the correct correlation coeficient \(r = \text{-}0.96\).

Unit 3, Lesson 8, Practice Problem 5. The solution for the residuals should be 0.087 and -0.033.

Unit 3, Lesson 10, Practice Problem 5. The solution for the residuals should be 2,069.23, -4,350.77, and 1,747.23.

Unit 4, Lesson 1, Practice Problem 3. The solution should not include choice E.

Unit 4, Lesson 7, Student Lesson Summary. One of the average rate of changes incorrectly showed that \(\frac{30-45}{6} = \frac{\text{-}15}{2}\). This has been corrected to \(\frac{\text{-}15}{6}\).

Unit 4, Lesson 7, Activity 3. Replaced the fraction \(\frac{17}{4}\) with \(\frac{17}{40}\) in the sample response for 1a.

Unit 4, Lesson 8, Practice Problem 7. The solution for the second question is \(t = 2\) instead of \(t = 4\).

Unit 4, Lesson 12, Activity 3. The solution for the second question now correctly states that the maximum number of hours is 12.

unit 4, Lesson 14, Activity 4. Equation 5 is corrected to \(y = \lvert x + 3 \rvert - 6\) to accurately match the graph given.

Unit 4, Lesson 16, Practice Problem 8. In the solution to part d, changed \(11 \le t \le 4.5\) to \(11 \le t \le 14.5\).

Unit 5, Lesson 1, Activity 3. For the last 2 questions, the switch occurs at day 19, not day 18.

Unit 5, Lesson 5, Practice Problem 1. The solution for parts b, c, and d used an incorrect equation. The solutions and graph have been updated.

Unit 5, Lesson 15, Practice Problem 1. The third part of this question now asks for the population \(t\) years after 2011.

Unit 5, Lesson 17, Practice Problem 3. The wording for the options is updated. The given interest percentages are not annual interest, but the percentage applied each time period.

Unit 5, Lesson 21, Activity 2. The solution for Paris in number 5 included the wrong values for 2010 and 2017. They should be 10,500,000 and 10,990,000 respectively.

Unit 5, Lesson 21, Activity 3. The world population hit 7 billion in 2011. The table and solution are updated to reflect this information.

Unit 6, Lesson 4, Activity 2. The images are updated to begin labeling the figures with step 0.

Unit 6, Lesson 6, Practice Problem 6. The image is updated to begin labeling the figures with step 0.

Unit 6, Lesson 7, Activity 3. The first question should be based on the equation \(A(x) = x \boldcdot \frac{(25-2x)}{2}\). The equation, image, and solution are updated to match the change.

Unit 6, Lesson 11, Practice Problem 4. The graphs for C and D are in the wrong order. The solution is C.

Unit 6, End of Unit Assessment, item 5c. The solution was listed in meters instead of feet.

Unit 6, End of Unit Assessment, item 6c. The solution included a shift to the left as well as down.

Unit 7, Lesson 2, Practice Problem 6. The solution now correctly uses values of $2x$ in the length and width terms.

Unit 7, Lesson 6 and Glossary. In the glossary entry for "constant term," changed the last number from 12 to -4.

Unit 7, Lesson 7, Practice Problem 7. All units should be in feet. The $y$-axis label for the image is updated to "height (feet)."

Unit 7, Lesson 11, Warm-up. A student response to the first item was missing, which should be "\(x\)".

Unit 7, Lesson 24, Practice Problem 8. Updated the equation for the second graph to \(g(x) = x^2 - 4x + 3\).