CON FRACCION

17.  4/5 -3/7 +1/2 -1/3 = -113/210

4/5 +1/2= 8+5/10 = +13/10

-3/7  -1/30= -9-7/21 = -16/21

-16/21 +13/10 = -113/210

18. 3/9 -3/2 = -27+6/18 = -21/18

19. -10/3 -5/2 -1/3 -4/6 = -522/108

-10/3 -5/2 = -20-15/6 = -35/6

-1/3  -4/6 = -6-12/18 = -18/18

-35/6 -18/18 = -630-108/108 = 522/108

20. +1/7 -13/10 = +10-91/70 = -81/70

21. -3/8 +-1/9 -1/3 = -46/192

-3/8 -1/3 =-8-9/24 = 17/24

-17/24+1/9 = -153+24/216 = 177/216

177/216 – 17/24 = 153-199/192 = - 46/192

22. 4/7 – 1/3 +3/2 = -196/588

4/7 + 3/2 = 21+8/14 = 13/14

13/14 -1/3 = 39-14/42 = 25/42

25/42 -13/14 = 350-546/588 = -196/588

23. 5/8 – 3/5 +1/7 -1/2 = -214/560

5/8 +1/7 = +35+8/56 = +27/56

3/5 -1/2 = -6-5/10 = -/10

+27/56 – 1/10 = 56-270/560 = 214/560

24.  -3/10 -1/7 +13/2 = -416/420

-3/10 -1/7 = -21-10/70 = -11/70

11/70 -1/7 = + 77-70/490 = -7/490

7/490 -11/70 = 63-479/420 = - 416/420

25. 7/2 -3/5 -2/3 +1/2 = -281/60

7/2 +1/2 = 21+2/4 = +19/4

-3/5 -2/3 = 9-10/15 = -1/15

19/4 -1/15 = -235-4/60 = -281/60

26. 3/2 +5 1/3 -9 1/7 =  +164/60

7/2 + 1/3 = 2+14/4 = +16/4

-3/5 -2/3 = -10-9/15 = -19/15

+16/4 -19/15 = -76+240/60 = +164/60