If f(x)=4x+3 and g(x)=x^2-3 what is f(g(4))

What is the axis of symmetry of the function f(x)=-(x+ 9)(x-21)

Apool measures 100 meters by 100 meters a toddler inside the pool and trows a ball 60 centimeters from one edge of the pool. how far is the ball from the opposite edge of the pool

Which expression is equal to (f+g)(x)?