Solve for X? I really need help please and need work to be shown as well

Use the quadratic formula to solve 5x=6x^2-3,what are the values of x?

Need on this geometry question. explain how you did it.

Astuntman jumping off a 20-m-high building is modeled by the equation h=20-5t^2, where t is the same in seconds. a high-speed camera is ready to film him between 15m and 10m above the ground. for which interval of time should the camera film him?