To find the slope of the above equation, it is easiest to put it into slope-intercept form, y=mx + b, where the variable m represents the slope. To do this, we must isolate the variable y on the left side of the equation by using the reverse order of operations. First, we should subtract 3x from both sides of the equation.
3x + 6y = 9
6y = -3x + 9
Next, we should divide both sides of the equation by 6 to undo the coefficent of 6 on the variable y.
y = -1/2x + 3/2
Therefore, the slope of the line is -1/2 (the coefficient of the variable x in slope-intercept form).
Hope this helps!