Find the value of 4n when n=3

The line y = x + passes through (−3, 7) and is parallel to y = 4x − 1.

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 to 2x^2+7x+4?