(X-2y)^4 Pakai cara yang benar

(x-2y) ^4
= ( (x-2y)² )²
= ( x² - 2(x)(-2y) + (-2y)² )²
= ( x² - 4xy + 4y² )²
= (x² - 4xy + 4y²) (x² - 4xy + 4y²)
= x²(x²) + x²(-4xy) + x²(4y²) + (-4xy)x² + (-4xy)(-4xy) + (-4xy)4y² + 4y²(x²) + 4y²(-4xy) + 4y²(4y²)
= x^4 - 4x³y + 4x²y² - 4x³y + 16x²y² - 16xy³ + 4x²y² - 16xy³ + 16y^4
= x^4 - 8x³y + 24x²y² - 32 xy³ + 16y^4

Semoga bermanfaat. ^_^ **