Points are (0,-8) and (-6,-3) Slope m = rise/run = Δy/Δx. [(-3 - (-8)]/[-6 - 0] = 5/-6 = -5/6
y = mx + b Using the (0,-8) point: -8 = 0x + b, so b = -8
The line is y = -5x/6 - 8 or (-5/6)x - 8. You can check via the Desmos Graphing Calculator site
I used the slope-intercept form, but you could also use the point-slope form (y2 - y1) = m(x2 - x1)