What's the answer to this​

Evaluate the dot product of (3,-1) and (1,5)

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 statement about perfect cubes is true