48% of 30 is about. what number. this is a estimation with percent

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

The square root of 9x plus 7 plus the square rot of 2x equall to 7

With alll of except for the 2 that i did already