multiply each term by each term and sum the results
[tex]\begin{gathered} (x\times x)+(x\times7)+(-3\times x)+(-3\times7) \\ x^2+7x-3x-21 \\ x^2+4x-21 \end{gathered}[/tex]so, the right option is B
the right option is A because
[tex]h^2+h-2[/tex]if we factor this expression by any way we obtain
[tex](h+2)(h-1)[/tex]