The slope is the x-coefficient when the equation is in slope-intercept form.
Slope-intercept form is y =mx + b
The "m" is the slope.
So just get the equation into that form.
2y = 6x - 8
Divide both sides by 2.
y = 3x - 4
Now it is in slope-intercept form. 3 is the x-coefficint, so 3 is the slope.