GIA'I PHU.O.NG TRNH

3)

Gia'i phu.o.ng trnh:

^a(xy

⁰

^{+ 2y) = xyy}

⁰

HD gia’i: a(xy

⁰

+ 2y) = xyy

⁰

⇒x(a−y)y

⁰

=−2ay

N^eu

^{y6= 0}

, ta co phu.o.ng trnh tu.o.ng du.o.ng vo.i

^a−yy dy =−2ax dx⇔x

^2a

y

^a

e

^−y

=C

Ngoai ra

^{y= 0}

cu~ng la nghi^e.m.