Why is the answer correct?

[tex]\bf x(2x+4x^2-5-3x)\implies x(\stackrel{\textit{like-terms}}{2x-3x}+4x^2-5)\implies x(-x+4x^2-5) \\\\\\ -x^2+4x^3-5x\implies \stackrel{\textit{general form}}{4x^3-x^2-5x}[/tex]
Answer:
Here's what I get.
Step-by-step explanation:
x(2x + 4x² - 5 – 3x)
1. Distribute the x
2x² + 4x³ - 5x - 3x²
2. Combine like terms
4x³ - 5x – x²
3. Write the expression in order of descending powers of x
[tex]\boxed{\mathbf{4x^{3} - x^{2} - 5x}}[/tex]