2y = x + 8
The standard form for a linear equation like this is:
y = mx + c , where 'm' is the slope (or gradient) and 'c' is the y-intercept (i.e. where the where the line goes through the y-axis)
So in this case, for your equation you need to get the y term on it's own to make it into the standard form.
This will happen if you divide both sides of the equation by 2:
2y = x + 8
(2y)/2 = (x + 8)/2
y = x/2 + 8/2
y = (1/2)x + 4 - this is the equation in the standard form.
So now you can see that the slope of the line is 1/2 and the y-intercept of the line is at (0, 4).