7) a(x + 1) + 5a(x - 1) = 2(3b - 2a)8) x(a + 1) - x(a - 1) = 2a + 49) (x + 2)(x - 5) = (x - 1)(x - 6)10) (x - 8)(x + 1) = (x + 5)(x - 3)?

7) ax + a + 5ax - 5a = 6b - 4a 6ax - 4a = 6b - 4a 6ax = 6b ax = b x = b / a

8) ax + x - ax + x = 2a + 4 2x = 2a + 4 2x = 2 (a + 2) x = a + 2

9) x2 + 5x + 2x - 10 = x2 - 6x - x + 6 x2 + 7x - 10 = x2 - 7x + 6 14x = 16 x = 16 / 14

10) x2 + x - 8x - 8 = x2 - 3x + 5x - 15 x2 - 7x - 8 = x2 + 2x - 15 7 = 9x x = 9 / 7.