The sum of (6a + 4b – c + 3), (2b – 3c + 4), (11b – 7a + 2c - 1) and (2c – 5a - 6) is

14

If x + y = 12 and xy = 14, find the value of (x² + y²).

15

If x – y = 7 and xy = 9, find the value of (x² + y²).

2

(3q + 7p² – 2r³ + 4) – (4p² – 2q + 7r³ – 3) = ?

3

(x + 5) (x - 3) = ?