Which is equivalent to 4x+4x+4x?

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?

How many solutions does the nonlinear system of equations graphed bellow have?

Is triangle jkl congruent to triangle rst? if so, what is the scale factor?