How can I tell if a triangle with side lengths 10, 24, and 26 is a right triangle?

30 is 6 multiplied by a number y as a equation

What is the nth term rule of the linear sequence below? 27 , 25 , 23 , 21 , 19 , . .

An airplane travels at an unknown elevation before it descends 3 miles to an elevation of 15 miles. find the elevation of the plane before its descen.