5/19+1.4/19×5.76-0.213×14/19+14/190×6.37 =5/19+14/190×5.76-0.213×140/190+14/190×6.37 =5/19+14/190×5.76-2.13×14/190+14/190×6.37=5/19+14/190×(5.76-2.13+6.37)=5/19+14/190×10=5/19+14/19=1