[tex]a = 3x + 1 \ \ \rightarrow \ \ 3x \neq -1 \ \ \rightarrow \ \ x\neq -\frac{1}{3}\\b = 2x-1 \ \ \rightarrow \ \ 2x\neq 1 \ \ \rightarrow \ \ x \neq \frac{1}{2}\\c = 2x+1 \ \ \rightarrow \ \ 2x \neq -1 \ \ \rightarrow \ \ x \neq- \frac{1}{2}\\\underline{D = R \setminus\{-\frac{1}{2}, -\frac{1}{3}, \frac{1}{2}\}}\\\\V = a\times b\times c\\\\V = (3x+1)(2x-1)(2x+1) = (3x+1)(4x^{2}-1) = 12x^{3}-3x+4x^{2}-1 =\\\\=\boxed{12x^{2}+4x^{2}-3x-1}[/tex]
Zastosowano wzór skróconego mnożenia:
(a - b)(a + b) = a² - b²
oraz:
(a + b)(c + d) = ac + ad + bc + bd
