What is the greatest common factor of 30,48,60

Find the measure of the interior angles of the following regular polygons: a triangle, a quadrilateral, a pentagon, an octagon, a decagon, a 30-gon, a 50-gon, and a 100-gon.

X+ y = 5 ; x - y =3 solve using linear combination

If x+y+z=0 what is the value of [tex] {x}^{3} + {y}^{3} + {z}^{3} [/tex]