TM TCH PH^AN T^O'NG QUAT CU'A CAC PHU.O.NG TRNH SAU

29)

Tm tch ph^an t^o'ng quat cu'a cac phu.o.ng trnh sau:

(x−y+ 4)dy+ (y+x−2)dx= 0HD gia’i:

D - ^ay la phu.o.ng trnh du.a v^e da.ng da'ng c^ap du.o..c bang cach da.t

^{x =}u+ 1, y = v−3,

ta du.o..c

_du^{dv =} _−u^u+₊^v_v

. Gia'i phu.o.ng trnh ta co nghi^e.m cu'a phu.o.ng

trnh la

^v

²

^−2uv−v

²

^=C.

V^a.y nghi^e.m cu'a phu.o.ng trnh da~ cho la

^y

²

^−x

²

^{−2xy−8y+ 4x=C}

¹

^.