1)dy/(y-1)=dx/(x+1)
ln(y-1)=ln(x+1)+C₁
y-1 =(x+1)·C
y=1+(x+1)·C
2)y²(1+x)dx=-x²(1-y)dy
(1+x)/x²·dx =- (1-y))/y²·dy
(1/x²+x/x²)dx= -(1/y²-y/y²)dy
(x⁻²+1/x)dx= - (y⁻²-1/y)dy
x⁻³/-3+lnx = y⁻³/3+lny+C
-1/3x³+lnx=1/3y³+lny+C
Нач.условия x=1 y=1
-1/3+ln1 = 1/3+ln1+C
C=-1/3-1/3=-2/3
-1/3x₃+lnx=1/3y³+lny-2/3