What is the chance of picking a even number out of 8 to 15

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

Solve x+3y=6 and 4x-6y=6 by elimination . show work !

Which function has the domain x> -11?