Evaluate :

(4 - ab) (8 + ab)

(4 - ab) (8 + ab)

= 4 (8 + ab) - ab (8 + ab)

= 32 + 4ab - 8ab - a⁽¹⁺¹⁾b⁽¹⁺¹⁾

= 32 - 4ab - a²b²

Hence, (4 - ab) (8 + ab) = 32 - 4ab - a²b²