Grade 6 Mathematics · Unit 7: Integers, Rational Numbers, and the Coordinate PlaneStandard 6.NOS.7

Lesson 7.97.9 Small Group · Group 2

Group 2 · Set BSecond challenge form · new problems, same idea

Mastery check☐ Exceeds☐ Meets target☐ Needs practice
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Learning target I can reflect points across the x-axis and y-axis on the coordinate plane, explain why the method works, and use it on a problem I have not seen before.

Remember7.9 Small Group · Group 2

Each reflection changes the sign of one coordinate, so you can undo a reflection or combine two of them. You can work backward from a reflection, and you can reflect a point across both axes.

Words: Reflection (Reflexión)x-axis (Eje x)y-axis (Eje y)Symmetry (Simetría)Integer (Número entero)

  1. 1Complete each step, then write the final answer.

    Point P is at (5, −1). Reflect it across the y-axis. Then reflect that point across the x-axis. Which quadrant is the final point in?

    Show your work
    Final answer:
  2. 2Complete each step, then write the final answer.

    Point T is reflected across the y-axis. Its image is at (−1.5, 7). What is the x-coordinate of T?

    Show your work
    Final answer:
  3. 3Complete each step, then write the final answer.

    A kite design is the same on both sides of the y-axis. One corner is at (−4, −6). What is the x-coordinate of the matching corner on the other side?

    Show your work
    Final answer:
  4. 4Complete each step, then write the final answer.

    Point P is at (a, 3) in Quadrant II. Its reflection across the y-axis is 12 units from P. What is a?

    Show your work
    Final answer:

Explain your thinkingLu changed both signs for one reflection. When does changing both signs work? Use a point and both axes to explain.

How did it go? ☐ 4 · I can teach it☐ 3 · I've got it☐ 2 · I need a hint☐ 1 · I need help