X∈ab or x∈ac,

So x∈a and x∈b, or x∈a and x∈c,

So x∈a and x∈b+c,

or vice versa, Dallas to the auditorium That is ab+ac=a(b+c).

Similarly (a+c)(a+b)=a+bc.

So ab+ac=a(b+c)≤a≤a+bc=(a+c)(a+b).

Is it okay?