$\displaystyle y' = 4t^2y^2$

Hint: write the ODE as (F(y))' = G(t).

I don't understand how to use the hint. I understand that I need to combine y' and y^2 into the form (F(y))'; I just don't know how.

I only got to $\displaystyle \frac{y'}{y^2} = 4t^2$

Thanks!