To find the slope of a line perpendicular to the given line, we first need to find the slope of the given line. We can rearrange the equation x + y = -6 to slope-intercept form y = -x - 6, where the slope is -1.
The slope of a line perpendicular to this line can be found by taking the negative reciprocal of the slope of the given line. The negative reciprocal of -1 is 1/1, which is just 1.
Therefore, the slope of a line perpendicular to the line x+y=-6 is 1.