Answer:
y = -1
Step-by-step explanation:
The slope-intercept form of the equation of a line has the form:
y = mx + b
Where m is the slope and b is the y-intercept.
The slope can be calculated as:
![m=(y_2-y_1)/(x_2-x_1)](https://img.qammunity.org/2023/formulas/mathematics/high-school/78uaqhwt0aws3qfwxigaftpihnmb1gzxtp.png)
Where (x1, y1) and (x2, y2) are the coordinates of two points in the line.
So, replacing (x1, y1) by (1, -1) and (x2, y2) by (2, -1), we get:
![m=(-1-(-1))/(2-1)=(-1+1)/(1)=(0)/(1)=0](https://img.qammunity.org/2023/formulas/mathematics/high-school/lxfdyqvdhbia0h4cpvx6gkd1zjssq2m3o4.png)
On the other hand, the y-intercept is the point where the line crosses the y-axis. So, the y-intercept is -1.
Finally, the equation of the line in the slope-intercept form is:
y = 0x - 1
y = -1
So, the answer is y = -1