[tex] (5x + 8)(4x^2 + 6x - 8)\\ \\ 5x(4x^2 + 6x - 8) + 8(4x^2 + 6x - 8) \\ \\ 20x^3 + 30x^2 - 40x + 8(4x^2 + 6x - 8) \\ \\ 20x^3 + 30x^2 - 40x + 32x^2 + 48x - 64 \\ \\ 20x^3 + (30x^2 + 32x^2) + (-40x + 48x) - 64 \\ \\ 20x^3 + 62x^2 + 8x - 64 \\ \\ [/tex]
The final result is: 20x^3 + 62x^2 + 8x - 64.
