Find the slope of a line perpendicular to the line whose equation is x, plus, y, equals, 9x+y=9. Fully simplify your answer.

To find the slope of the line given by the equation 9x + y = 9, we need to rearrange the equation into the slope-intercept form, y = mx + b, where m is the slope of the line.

9x + y = 9
y = -9x + 9

So, the slope of the line given by the equation 9x + y = 9 is -9.

The slope of a line perpendicular to this line is the negative reciprocal of -9. The negative reciprocal of a number is found by taking the negative of the reciprocal of the number.

Reciprocal of -9 is -1/9.

The negative of -1/9 is 1/9.

Therefore, the slope of a line perpendicular to the line 9x + y = 9 is 1/9.