Sottogruppi H 1 = { 1 , x , x 2 , x 3 } ciclico {\displaystyle H_{1}=\{1,x,x^{2},x^{3}\}\quad {\hbox{ciclico}}} H 2 = { 1 , x 2 , y , x 2 y } {\displaystyle H_{2}=\{1,x^{2},y,x^{2}y\}} H 3 = { 1 , x 2 , x y , x 3 y } {\displaystyle H_{3}=\{1,x^{2},xy,x^{3}y\}} H 4 = { 1 , y } {\displaystyle H_{4}=\{1,y\}} H 5 = { 1 , x 2 } {\displaystyle H_{5}=\{1,x^{2}\}} H 6 = { 1 , x y } {\displaystyle H_{6}=\{1,xy\}} H 7 = { 1 , x 2 y } {\displaystyle H_{7}=\{1,x^{2}y\}} H 8 = { 1 , x 3 y } {\displaystyle H_{8}=\{1,x^{3}y\}}