(2x² + 3)(4x +5) -8x(x²-2)
2x²(4x + 5) + 3(4x + 5) - 8x(x² - 2)
8x³ + 10x² + 12x + 15 - 8x³ - 2
= 8x³ - 8x³ = 0
= 10x² + 12x + 15 - 2
= 10x² + 12x + 13