Answer:
y = -x - 1
Explanation:
To write this equation in slope intercept form, we will first familiarise ourselves with the formula.
The formula for slope intercept is y = mx + b, where the parameter m tells us the slope and the parameter b tells us the y-intercept of the line.
If we know these two parameters, we have enough information to write the equation of the line.
So now let's rewrite the equation "x + y = -1" in "y = mx + b" form.
x + y = -1
y = -1 - x
y = -x - 1