The vertex of the parabola f(x)= -5x^2+4x+1 is the point

Need ! give step by step solutions on how to solve number one \frac{9-2\sqrt{3} }{12+\sqrt{3} } number two x+4=\sqrt{13x-20} number three (domain and range) f(x)=2\sqrt[3]{x} +1

Which expression is equivalent to7_/x^2 ÷ 5_/y^3? assume y# 0

How to do this , and can some one explain