Question

2abc - 3ab if a=2 b=-3 and c=4

Answer 1

2abc - 3ab ║ 2 (2) (3) (4) - 3 (2) (3)

You would multiply and the products - you are going to subtract
2 × 2 × 3 × 4 = 48
3 × 2 × 3 =     - 18
                    -------
        answer:    30

Answer 2

2*2*-3*4= -48

-3*2*-3= 18

answer will be -30 not 30