Find the common factor:
ab+bc ab+bc ab+bc
ab+bc=a×b+b×c ab+bc=a\times b+b\times c ab+bc=a×b+b×c
If we consider that b is the common factor, it can be removed from the equation:
b(ab+bc)= b(ab+bc)= b(ab+bc)=
We divide by b:b(abb+bcb)= b(\frac{ab}{b}+\frac{bc}{b})= b(bab+bbc)=
b(a+c) b(a+c) b(a+c)