x² - 9x - 10 is equal to :

1. (x - 10) (x + 1)

2. (x - 10) (x - 1)

3. (x + 10) (x - 1)

4. (x + 10) (x + 1)

x² - 23x + 42 is equal to :

1. (x - 21) (x + 2)

2. (x - 21) (x - 2)

3. (x + 21) (x + 2)

4. (x + 21) (x - 2)

(x + y)² - 3(x + y) - 4 is equal to :

1. (x + y + 4) (x + y - 1)

2. (x + y + 4) (x + y + 1)

3. (x + y - 4) (x + y + 1)

4. (x + y - 4) (x + y - 1)

60 + 11x - x² is equal to :

1. (4 + x) (15 - x)

2. (4 - x) (15 - x)

3. (4 - x) (15 + x)

4. (4 + x) (15 + x)