2/11+4/11+1/11+1/11+2/11==(2+4+1+1+2)×1/11=10×1/11=10/11
2/11+4/11+1/11+1/11+2/11=(1/11+1/11)+(2/11+2/11)+4/11=2x1/11+2x2/11+4/11=2/11+4/11+4/11=10/11