12=a+5b solve for a. i think the answer is 12-5b=a but that's probably wrong

4. find the geometric mean of 4 and 12. 24 8

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]

What is x and y intercepts for y=x+7