1 4/9×5/113-1/212×4/15=16.826/317.205;
1)1 4/9×5/133=13/9×5/133=13×5/9×133=65/1.197;
2)1/212×4/15=1×4/212×15=4/3.180=1/795;
3)65/1.197-1/795=65×265/317.205-1×399/317.205=17.225-399/317.205=16.826/317.205;
1 4/9×5/113-1/212×4/15=16.826/317.205;
1)1 4/9×5/133=13/9×5/133=13×5/9×133=65/1.197;
2)1/212×4/15=1×4/212×15=4/3.180=1/795;
3)65/1.197-1/795=65×265/317.205-1×399/317.205=17.225-399/317.205=16.826/317.205;