15. What is the slope of the line with the equation $2 x+3 y+6=0$ ? A. -6 B. -3 C. -2 D. $-\frac{2}{3}$ E. $\frac{2}{3}$

Step 1 ：The slope of a line in the form \(ax + by + c = 0\) is \(-\frac{a}{b}\).

Step 2 ：In this case, \(a = 2\) and \(b = 3\).

Step 3 ：So, the slope of the line is \(-\frac{2}{3}\).

Step 4 ：The slope of the line is -0.6666666666666666, which is equivalent to \(-\frac{2}{3}\) when expressed as a fraction.

Step 5 ：Final Answer: \(\boxed{-\frac{2}{3}}\)