Help please I really don’t understand this

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]

Angel entered a triathlon (a three-part race). he swam 1 mile, rode his bike 30 miles, and ran 10 miles. how far did he go altogether? a. 11 miles b. 123 miles c. 41 miles d. 40 miles

Ineed me i stuck and i don’t want to get it wrong