2.7. Miscelánea
de
Ecuaciones Diferenciales
81
21.
(x
+ye~)dx
-
xe~dy
= O
22.
(x2
+
y2
+
x )dx
+
xydy
= O
23 .
dy
dx
+
x
+
y
+
1 =
(x
+
y)2e'x
24.
dy
3
- =
y(xy
-
1)
dx
25.
x
dx
+ (- -
sen
y)dy
= O
Y
26.
(y2
+
3xy)dx
=
(4x 2
+
xy)dy
27. dy
=
I -
Iy
+
3x
-
2
dx
V
28. x 2dx
+
(1 -
x3y )dy
=
O
dy
29 . Y
+
x (1n x
-
ln y - 1)
dx =
O
30. (6x 2y
+
12xy
+
y2)dx
+
(6x 2
+
2y )dy
=
O
31.
(x 2
+
xy
+
3y2) dx
-
(X2
+
2xy)dy
=
O
32. (y lny
+
yeX)dx
+
(T
+
ycosy)dy
=
O
33. y2(xy'
+
y)( 1
+
x
4
)!
=
x
dy
Y
- 2
35. 2-
= - -
xy
dx
x
36. (2xy
+
3y2)dx
=
(2xy
+
x 2 )dy
37. 6xydx
+
(4y
+
9x 2 )dy
=
O
38. xy'
-
y
-
x 2 cosx
=
O,
con
y(rr)
=
I
39. (2x+ tany )dx+ (x -x 2 tan y)dy
=
O
40 . y 2dx
+
(xy
-
x 3 )dy
=
O
41.
dy
=
=2=-XY,,--2_+~y
dx
x-2y3
42 . xydx
-
x 2dy
=
YVX2
+
y 2dy
1...,73,74,75,76,77,78,79,80,81,82 84,85,86,87,88,89,90,91,92,93,...252