ab – a – b + 1 = (a – 1) (1 – b)
ab – a – b + 1 = (a – 1) (1 – b)
ab – a – b + 1 = (a – 1) (b – 1)
ab – a – b + 1 = (a – 1) (b – 1)
ab + a – b + 1 = (1 – a) (1 – b) (1 – a) (1 + b)
ab + a – b + 1 = (1 – a) (1 – b) (1 – a) (1 + b)
ab – a – b + 1 = (1 – a) (b – 1)
ab – a – b + 1 = (1 – a) (b – 1)
Correct Answer:
ab – a – b + 1 = (a – 1) (b – 1)
ab – a – b + 1 = (a – 1) (b – 1)
