The differential equation bx [a y sin (5x) + 2e'* cos(4y) +mx²] dx + [cos(cx) + 2eb* sin(4y)] dy = 0 is exact for a = -5, b = −4, c = 5, m any real is exact for a = −5, b = 5, c = -4, m any real is exact for b = -4, c = 5 and any reals a, m is exact for a = −5, b = −4, c = 5, m = 0 only is never exact The differential equation x-4 y² dx + (y² + x¯³ y² + 6) dy = 0 is non exact and has integrating factor μ(y) non exact and has integrating factor μ(x) non exact and has integrating factor μ(y) non exact and has integrating factor μ(y) = = = уг езу x2 е x -2 -3 y е = y³ e² y exact non exact and has integrating factor μ(x) =x-2-3x