$2$ Solve the following exact equations.

a$)(2xy+x^2)dx+(x^2+y^2+1)dy=0$

b$)x^5+y^5{y}^{\text{'}}=0$

c$)e^x+y^3+3x{y}^2\frac{dy}{dx}=0$

d$)(x+y)cos(x)+sin(x)+sin(x)y^{\text{'}}=0$