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Home > CC4 > Chapter 8 > Lesson 8.1.3 > Problem 8-43

8-43.
  1. Mary says she can find the x‑intercept of the equation −4x + 5y = 16 by substituting 0 for x, while Michelle says she needs to substitute 0 for y. Homework Help ✎

    1. Who, if anyone, is correct and why?

    2. Use the correct approach to determine the x‑intercept.

One way to view this is graphically: the x-intercept lies anywhere along the x-axis.

Michelle is correct. The x-intercept always has a y-coordinate of 0 because it lies on the x-axis.

Substitute 0 for y and then solve for x.