lg50+lg2*lg5+(lg2)^2
=(lg2)^2+lg2lg5+lg(25*2)
=(lg2)^2+lg2lg5+2lg5+lg2
=lg2(lg+lg5)+2lg5+lg2
=lg2*1+2lg5+lg2
=2(lg5+lg2)
=2lg10
=2