Question

Prove that : 1+a+b+ab=(1+a) (1+b)​

Answer 1

The solution is here. See this

Answer 2

1 + a + b + ab = (1+a)(1+b)

Take RHS

(1+a)(1+b)=1 (1+b)+a(1+b)=1+b+a+ab

Hope you Understood

Hence

LHS =RHS