Find the mean of the following numbers 7,21,2,17,3,13,7,4,9

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¯¯¯¯¯¯¯¯)?

Select a graph that have an equation with a < 0

What is the value of x in the following equation. -x ^3/2 = -27