4/9÷1/17 +19×4/9=4/9×17 +19×4/9=4/9×(17+19)=4/9×36=16
4/9 ÷1/17+19 ×4/9=4/9 ×17+19 ×4/9=4/9 × (17+19)=4/9 ×36=16