What is a line parallel to y=-x-6 that passes through (-9,-4)?

Slope-intercept form:  y = mx + b

(m is the slope, b is the y-intercept or the y value when x = 0 --> (0, y) or the point where the line crosses through the y-axis)

For lines to be parallel, they need to have the same slope.

y = -x - 6      The slope is -1, so the parallel line's slope is also -1.

Now that you know the slope, substitute/plug it into the equation:

y = mx + b

y = -x + b      To find b, plug in the point (-9, -4) into the equation, then isolate/get the variable "b" by itself

-4 = -(-9) + b  (two negative signs cancel each other out and become positive)

-4 = 9 + b     Subtract 9 on both sides to get "b" by itself

-4 - 9 = 9 - 9 + b

-13 = b

y = -x - 13