Write the number halfway between 3 and 4

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

Including 6% sales tax, an inn charges $135.68 per night. find the inns nightly cost

Ab and bc are tangent to circle d. find x is ab = 3x + 8 and bc = 26. find x