Home > CC4 > Chapter 8 > Lesson 8.1.3 > Problem8-43

8-43.

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?

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.

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

Substitute $0$ for $y$ and then solve for $x$.