lg72=lg(3*3*2*2*2)=lg3+lg3+lg2+lg2+lg2=2lg3+3lg2=2*0.4771+3*0.301=0.9542+0.903=1.8572
lg4.5=lg(3*3/2)=lg3+lg3-lg2=2lg3-lg2=2*0.4771-0.301=0.9542-0.301=0.6532
lg72=lg(3*3*2*2*2)=lg3+lg3+lg2+lg2+lg2=2lg3+3lg2=2*0.4771+3*0.301=0.9542+0.903=1.8572
lg4.5=lg(3*3/2)=lg3+lg3-lg2=2lg3-lg2=2*0.4771-0.301=0.9542-0.301=0.6532