Given expression: [tex](x^4)(3x^3-2)(4x^2+5x)[/tex].We need to simplify the given expression by multiplying.[tex]\mathrm{Expand}\:\left(3x^3-2\right)\left(4x^2+5x\right):\quad 12x^5+15x^4-8x^2-10x[/tex][tex]=\left(x^4\right)\left(12x^5+15x^4-8x^2-10x\right)[/tex][tex]\left(x^4\right)\left(12x^5+15x^4-8x^2-10x\right):\quad 12x^9+15x^8-8x^6-10x^5[/tex][tex]=12x^9+15x^8-8x^6-10x^5[/tex]Therefore, [tex]\left(x^4\right)\left(3x^3-2\right)\left(4x^2+5x\right)=\quad 12x^9+15x^8-8x^6-10x^5.[/tex].