Question

write the equation of the line.

Explanation:

Step1: Identify the line type

The line is horizontal, so its slope \( m = 0 \).

Step2: Find the y - intercept

A horizontal line has the equation \( y = k \), where \( k \) is the y - coordinate of all points on the line. From the graph, the line passes through points with \( y=-30 \) (since it's 3 units below the origin on the y - axis, each grid line seems to be 10 units? Wait, looking at the grid, the line is at \( y=-30 \)? Wait, no, looking at the graph, the horizontal line is at \( y = - 30\)? Wait, no, let's check the grid. The y - axis has marks at - 100, - 80, - 60, - 40, - 20, 0, 20, 40, 60, 80, 100. The horizontal line is passing through \( y=-30 \)? Wait, no, maybe each grid square is 10 units. Wait, the line is horizontal, so for any \( x \), \( y \) is constant. Looking at the line, it's at \( y=-30 \)? Wait, no, let's see: the line is drawn such that it's a horizontal line. Let's take two points on the line. For example, when \( x = 0 \), \( y=-30 \)? Wait, no, maybe I misread. Wait, the line is at \( y=-30 \)? Wait, no, the line is at \( y=-30 \)? Wait, actually, looking at the graph, the horizontal line is at \( y=-30 \)? Wait, no, let's check the y - axis. The line is below the x - axis, and each grid line is 10 units. So the line is at \( y=-30 \)? Wait, no, maybe it's \( y = - 30\)? Wait, no, let's think again. A horizontal line has equation \( y = b \), where \( b \) is the y - intercept. From the graph, the horizontal line is at \( y=-30 \)? Wait, no, looking at the graph, the line is at \( y = - 30\)? Wait, maybe the line is \( y=-30 \). Wait, no, let's check: when \( x = 0 \), the y - coordinate of the line is - 30? Wait, maybe I made a mistake. Wait, the line is horizontal, so slope \( m = 0 \). The equation of a line is \( y=mx + b \). Since \( m = 0 \), the equation is \( y=b \). From the graph, the line is at \( y=-30 \)? Wait, no, looking at the grid, the line is at \( y=-30 \)? Wait, maybe the correct y - intercept is - 30? Wait, no, let's look at the graph again. The horizontal line is drawn at \( y=-30 \)? Wait, perhaps the line is \( y=-30 \). So the equation is \( y=-30 \).

Wait, maybe I messed up the grid. Let's see: the y - axis has ticks at - 100, - 80, - 60, - 40, - 20, 0, 20, 40, 60, 80, 100. The horizontal line is between - 40 and - 20? Wait, no, the line is at \( y=-30 \)? Wait, no, each grid square is 10 units. So from \( y=-40 \) to \( y=-20 \) is 20 units, so the middle would be \( y=-30 \). So the line is \( y=-30 \).

Answer:

\( y=-30 \)