Question

$(2\mathbf{a} + 3\mathbf{b}) \times (5\mathbf{a} + 7\mathbf{b}) =$

• A. $\mathbf{a} \times \mathbf{b}$
• B. $\mathbf{b} \times \mathbf{a}$
• C. $\mathbf{a} + \mathbf{b}$
• D. $7\mathbf{a} + 10\mathbf{b}$

Answer 1

Answer: (B)

$\mathbf{b} \times \mathbf{a}$

Answer 2

$14(\mathbf{a} \times \mathbf{b}) + 15(\mathbf{b} \times \mathbf{a}) = \mathbf{b} \times \mathbf{a}$.