Which set of side lengths can form a triangle? a 6cm, 8cm, 18cm b 6cm, 8cm, 10cm c 6cm, 7cm, 14cm d 6cm, 7cm, 20cm

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

Answer this question! 30 points and brainliest! only if you know the answer.

What is the solution to the equation? k/6.4=8.7 2.3 5.568 15.1 55.68