Question

so in this equation x + 2y= -8
would the slope be 1 ?

Answer 1

x + 2y = -8

Subtract 'x' to both sides:

2y = -x - 8

DIvide 2 to both sides:

y = -1/2x - 4

Slope is -1/2, not 1.

Answer 2

No.
$x+2y=-8\\ 2y=-x-8\\ y=-\dfrac{1}{2}x+4\\\\ m=-\dfrac{1}{2}$