Which equals the product of (x - 3)(2x + 1)

We need to multiply (x - 3) by (2x + 1).

$\begin{array}{l}\left(\mathrm{x}-3\right)\left(2\mathrm{x}+1\right)\\ =\mathrm{x}\left(2\mathrm{x}+1\right)-3\left(2\mathrm{x}+1\right)\\ =\left(\mathrm{x} \times 2\mathrm{x}\right)+\left(\mathrm{x} \times 1\right)-\{\left(3 \times 2\mathrm{x}\right)+\left(3 \times 1\right)\}\\ =2{\mathrm{x}}^2+\mathrm{x}-\{6\mathrm{x}+3\}\\ =2{\mathrm{x}}^2-5\mathrm{x}-3\end{array}$

The product of $\left(\mathrm{x}-3\right)\left(2\mathrm{x}+1\right)$ is $2{\mathrm{x}}^2-5\mathrm{x}+3$