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Five-Minute Check (over Lesson 8–2) Then/Now New Vocabulary Example 1: Use a Table of Ordered Pairs Example 2: Real-World Example: Use Function Equations Example 3: Graph a Linear Function Lesson Menu

Which equation best describes the sequence 2, 4, 6, 8, …? A. t = 2n B. C. t = 4n D. t = 2n + 2 5-Minute Check 1

Which equation best describes the sequence 10, 20, 30, 40, …? A. t = n + 10 B. t = 10n C. D. t = 10n 5-Minute Check 2

Which equation best describes the sequence 9, 10, 11, 12, …? A. t = n + 1 B. t = 9n C. t = n + 8 D. t = n + 9 5-Minute Check 3

Find the 14th term of the sequence 7, 8, 9, 10, …. A. 14 B. 16 C. 18 D. 20 5-Minute Check 4

Find the 22nd term of the sequence 7, 10, 13, 16, …. A. 74 B. 72 C. 70 D. 68 5-Minute Check 5

Jimmy increased his trumpet practice by 10 minutes each week Jimmy increased his trumpet practice by 10 minutes each week. He practiced 15 minutes during Week 1. How many minutes did he practice during Week 12? A. 95 B. 105 C. 115 D. 125 5-Minute Check 6

Solve linear equations with two variables. You used functions to describe relationships between two quantities. (Lesson 1–5) Solve linear equations with two variables. Graph linear equations using ordered pairs. Then/Now

linear equation x-intercept y-intercept discrete data Vocabulary

Use a Table of Ordered Pairs Find four solutions of y = 4x + 3. Write the solutions as ordered pairs. Choose four values for x. Then substitute each value into the equation to solve for y. There are many possible solutions. The solutions you find depend on which x-values you choose. Example 1

Use a Table of Ordered Pairs Sample Answer: Four possible solutions are (0, 3), (1, 7), (2, 11), and (3, 15). Example 1

Find four solutions of y = 2x – 4. A. (1, –2), (3, 2), (5, 1), and (7, 10) B. (–2, 0), (0, –4), (2, 0), and (4, 4) C. (0, –4), (1, –2), (2, 2), and (3, –1) D. (0, –4), (1, –2), (2, 0), and (3, 2) Example 1

First, rewrite the equation by solving for y. Use Function Equations BUSINESS At a local software company, Level 1 employees x earn $48,000 and Level 2 employees y earn $24,000. Find four solutions of 48,000x + 24,000y = 216,000 to determine how many employees at each level the company can hire for $216,000. Explain each solution. First, rewrite the equation by solving for y. Example 2

48,000x + 24,000y = 216,000 Write the equation. Use Function Equations 48,000x + 24,000y = 216,000 Write the equation. 24,000y = 216,000 – 48,000x Subtract 48,000x from each side. Divide each side by 24,000. y = 9 – 2x Simplify. Example 2

Choose four x-values and substitute them into y = 9 – 2x. Use Function Equations Choose four x-values and substitute them into y = 9 – 2x. Sample Answer: (0, 9), (1, 7), (2, 5), and (3, 3) 0 employees at Level 1, 9 employees at Level 2 1 employee at Level 1, 7 employees at Level 2 2 employees at Level 1, 5 employees at Level 2 3 employees at Level 1, 3 employees at Level 2 Example 2

BOOKS At a local bookstore, hardbacks are on sale for $6 and paperbacks are on sale for $3. Bob has $42 to spend on books. Find four solutions to determine how many books of each type Bob can buy with his $42. A. 0 hardbacks, 42 paperbacks 3 hardbacks, 24 paperbacks 5 hardbacks, 12 paperbacks 7 hardbacks, 0 paperbacks B. 0 hardbacks, 14 paperbacks 1 hardbacks, 12 paperbacks 2 hardbacks, 10 paperbacks 3 hardbacks, 8 paperbacks C. 0 hardbacks, 42 paperbacks 3 hardbacks, 24 paperbacks 5 hardbacks, 9 paperbacks 7 hardbacks, 7 paperbacks D. 0 hardbacks, 14 paperbacks 1 hardbacks, 8 paperbacks 2 hardbacks, 2 paperbacks 3 hardbacks, –4 paperbacks Example 2

Step 1 Find the x-intercept. To find the x-intercept, let y = 0. Graph a Linear Function Graph y = x + 2. Step 1 Find the x-intercept. To find the x-intercept, let y = 0. y = x + 2 Write the equation. 0 = x + 2 Replace y with 0. –2 = x Subtract 2 from each side. Since x = –2 when y = 0, graph the ordered pair (–2, 0). Example 3

Step 2 Find the y-intercept. Graph a Linear Function Step 2 Find the y-intercept. y = x + 2 Write the equation. y = 0 + 2 Replace x with 0. y = 2 Simplify. Since y = 2 when x = 0, graph the ordered pair (0, 2). Step 3 Connect the points with a line. Example 3

Graph a Linear Function Check Check another point in the equation. If x = 1, y = 1 + 2 or 3. Notice that (1, 3) is on the graph of the line. Example 3

Graph y = 5 – x. A. B. C. D. Example 3

End of the Lesson