What is the value of the remaining variable? p=2l+2w; l=68, w=71

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

Divide. write in simplest form 41/6 divided by 10

Will gve pints stars and brainliest