※ 引述《semmy214 (黃小六)》之銘言：
: https://imgur.com/a/49H88
: 這方法我還不太熟~
: 請各位大大 指導~
(-5v + 2u)du + (-2u - 4v)dv = 0
v = ku
dv = udk + kdu
(-5k + 2)udu + (-2 - 4k)u[udk + kdu] = 0
=> [(-5k + 2)u + (-2k - 4k^2)u]du + (-2 - 4k)u^2 dk = 0
=> (1/u)du + [-2(1 + 2k)/(-4k^2 - 7k + 2)]dk = 0
=> dln|u| - 2[-(4/3)/(-4k + 1) + (2/3)/(k + 2)]dk = 0
=> ln|u| - (2/3)ln|k - 1/4| - (4/3)ln|k + 2| = c
=> ln|u| - (2/3)ln|v/u - 1/4| - (4/3)ln|v/u + 2| = c
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