1) (2a - 3b)² = (2a)² - 2 * (2a) * (3b) + (3b)² = 4a² - 12ab + 9b²
2) (8x³ - 6y)(8x³ + 6y) = (8x³)² - (6y)² = 64x⁶ - 36y²
3) (-3p⁴ - 5k⁶)² = (-3p⁴)² - 2 * (-3p⁴) * (5k⁶) + (-5k⁶)² = 9p⁸ + 30p⁴k⁶ + 25k¹²
4) (3y⁵m + 4ym)² = (3y⁵m)² + 2 * (3y⁵m) * (4ym) + (4ym)² = 9y¹⁰m + 24y⁶m² + 16y²m²