guys im realllly bad at these i need to get them in for extra credit to boost my gpa gimmi a hand?

Solve

a)dx/dt = -t power 4

b)dy/dt = 4 / y power 2 + 3

c)dy/dx = -8 y power 3

d) xy dy/dx = x + 4x power 2 / 5y

2)solve with subsittution y=vx

dy/dx= 6xy/x power 2 - y power 2