\(-5 (2 a + 6 b) = -10 a - 30 b\)

\(-9 + (7 a - 8) = -9 + 7 a - 8 = 7 a - 17\)

\(2 - (4 p + 5) = 2 - 4 p - 5 = -4 p - 3\)

\(-9 (-8 x + 4) = 72 x - 36\)

\(-3 (6 x + 4) + 2 (5 x - 8) = -18 x - 12 + 10 x - 16 = -8 x - 28\)

\(-3 a (-2 a - 7) = 6 a^{2} + 21 a\)

\((7 x + 4) + (3 x + 8) = 7 x + 4 + 3 x + 8 = 10 x + 12\)

\((-2 a - 3) - (6 a + 4) = -2 a - 3 + -6 a - 4 = -8 a - 7\)

\(5 (3 x - 9 y - 4) = 15 x - 45 y - 20\)

\((8 p - 6) (-9 q - 7) = -72 p q - 56 p + 54 q + 42\)

\((9 x + 3) (7 x - 8) = 63 x^{2} - 72 x + 21 x - 24 = 63 x^{2} - 51 x - 24\)

\((a - 6) (a - 5) = a^{2} - 5 a - 6 a + 30 = a^{2} - 11 a + 30\)

\((a - 7)^{2} = a^{2} - 14 a + 49\)

\((6 a + 9)^{2} = 36 a^{2} + 108 a + 81\)

\((-7 p + 2 q)^{2} = 49 p^{2} - 28 p q + 4 q^{2}\)

\((x + 8) (x + 9) (x + 4) = (x + 8) (x^{2} + 13 x + 36) = x^{3} + 13 x^{2} + 36 x + 8 x^{2} + 104 x + 288 = x^{3} + 21 x^{2} + 140 x + 288\)

\(x (x + 3) (x + 9) = x (x^{2} + 12 x + 27) = x^{3} + 12 x^{2} + 27 x\)

\((4 p - 8 q) (4 p + 8 q) = 16 p^{2} - 64 q^{2}\)

\((-3 a + 9) (-3 a - 9) = 9 a^{2} - 81\)

\((a - 2) (a + 2) = a^{2} - 4\)