Which operations is the following set closed under? Explain your answer. \(\eft\{2,4,6\right\})

Arley is building a model of a city map. in one part of the city, three roads form a right triangle, which harley draws as triangle abc, with the following measures: m∠b=90° and m∠a=30°. in his scale model, the hypotenuse of triangle abc, ac¯¯¯¯¯¯¯¯, has a length of 817−−√ cm. what is the value of a (the length of bc¯¯¯¯¯¯¯¯)?

Which value would be a solution for x in the inequality 47-4x< 7

What is the radical expression that is equivalent to the expression 27 1 over 5?