X+2y+6=0
solve for the value of "y"
and explain how to graph the result.

X + 2y + 6 = 0

Subtract (x + 6) from each side :

2y = -x - 6

Divide each side by 2 :

y = -1/2 x - 3

When the equation is in this form, you can look at it and know immediately
that the slope of its graph is -1/2 and its graph crosses the y-axis at y= -3.

In order to graph it, draw a straight line with a slope of -1/2 through the point
on the y-axis where y= -3 .