Question

Which is true about the line whose equation is y + 2 = 0?

The line is vertical.
The y-intercept is -2.
The slope is undefined.
The value of x always equals the value of y.

Answer 1

Solve for y and place it into y = mx + b form

what do you get?

Answer 2

the y-intercept is -2

*its not a vertical line, indeed a horizontal parallel to x-axis
*the value of y is always -2 and not equal to x
*the slope is 0.