(4-x)² = 16²-8x+x(-2-3y)(4-8y) = -6+16y-12y+24y = 28y-6
(4 - x)² = 16 - 8x + x²
= x² - 8x + 16
(-2 - 3y)(4 - 8y) = -8 + 16y - 12y + 24y²
= 24y² + 16y - 8