The radius of a circle is 7.2 cm. Find the circumference to the nearest tenth. please help !

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]

Lines a and b are parallel. what is the value of x? -5 -10 -35 -55

What ia the sum if the first 7 terms of the geometric series