Hasil dari (2x+2y)2 [pangkat 2] - 2 (5x-2y)2 [pangkat 2]

(2x+2y)^2 - 2 (5x-2y)^2
= {(2x+2y)(2x+2y)} - 2 {(5x-2y)(5x-2y)
= {4x^2+8xy+4y^2} - 2 {25x^2-20xy+4y^2}
= {4x^2+8xy+4y^2} - {50x^2-40xy+8y^2}
= 4x^2+8xy+4y^2-50x^2+40xy-8y^2
= (4-50)x^2+(8+40)xy+(4-8)y^2
= -35x^2+48xy-4y^2

Keterangan:
^ artinya pangkat