In problems 9-12, a family of solutions of a differential equation is given. Find the value of the constant C so the solution satisfies the initial value condition.
9. y' = 2x and y(3) 7. y=x² + C. 10. y- = 3x - 5 and y(1) = 2. y=x³-5x+C
11. y' = 3y² and y(0) = 5. y=Ce^3x
12. y' = -2y and y(0)=3. y = Ce^=2x