To find the slope, u need to put the equation in y = mx + b form, where m will be ur slope.
2x - 4y = 10 ... subtract 2x from both sides
-4y = -2x + 10...divide both sides by -4
y = (-2/-4)x + (-10/4)
y = 1/2x - 5/2
y = mx + b
y = (1/2)x - 5/2
the slope(m) = 1/2