b² - ac - bc + ab =

1. (a + b)(b - c)

2. (b - a)(b - c)

3. (a - b)(b + c)

4. (a - b)(b - c)

The value of (1 + x)²(1 + y²) - (1 + x²)(1 + y)² is:

1. 2(x - y)(1 + xy)

2. (x - y)(1 - xy)

3. 2(x - y)(1 - xy)

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

16(2a − b)² − 9(a + b)² =

1. (5a − 7b)(11a − b)

2. (5a + 7b)(11a − b)

3. (5a − 7b)(11a + b)

4. (5a + 7b)(11a + b)

Factorization of 3a(3a + 2c) − 4b(b + c) is:

1. (3a + 2b)(3a + 2b + 2c)

2. (3a − 2b)(3a − 2b + 2c)

3. (3a − 2b)(3a + 2b + 2c)

4. (3a − 2b)(3a + 2b − 2c)