Question

(3a-1by2)(3a+7by 2)​

Answer 1

$(\frac{3a - 1}{2})( \frac{3a + 7}{2} ) \\ \\ \frac{ {(3a)}^{2} + ( - 1 + 7)3a + ( - 1 \times 7) }{2 \times 2} \\ \\ \frac{ {9a}^{2} + 18a - 7 }{4}$