求(x/2)-(y/5)=4的斜率 (要列式)

求(x/2)-(y/5)=4的斜率,(要列式),(即此式δy/δx的值)
Method 1
5x - 2y = 40
2y = 5x - 40
y = 5x/2 - 20
By y = mx+c, m = 5/2 = slope

Method 2

1/2 - (1/5)(δy/δx) = 0
(1/5)δy/δx = 1/2
δy/δx = 5/2