Question

a) (-7 supra 36+(-5 supra 18+(-1 supra 24)+(+11 supra 48)= b) (- 4 supra 21 )+(- 6 supra 7)+(+ 5 supra 42)+(+9 supra 14) = c) (+3 supra 4)+(-5 supra 24)+(7 supra 8)+(-1 supra 16)= d) (-5 supra 48)+(+7 supra 18)+(-1 supra 36)+(-11 supra 12= e) -3 2 supra 5 -(-4 3 supra 10)-(+2 4 supra 15)=

Answer 1

a)-7/36 - 5/18 - 1/24 + 11/48 =

Numitor comun 

36=2²·3²

18=2·3²

24=2³·3

48=2⁴·3

______

c.m.m.m.c.=2⁴·3²=144

-28/144 - 40/144 - 6/144 + 33/144 = -41/144

b)-4/21 - 6/7 + 5/42 + 9/14 = 

Numitor comun 42

-8/42 - 36/42 + 5/42 + 27/42 = -12/42 = -2/7

c)3/4 - 5/24 + 7/8 - 1/16 = 

Numitor comun 48

36/48 - 10/48 + 42/48 - 3/48 = 65/48

d)-5/48 + 7/18 - 1/36 - 11/12 = 

Numitor comun 

48=2⁴·3

18=2·3²

36=2²·3²

12=2²·3

______

c.m.m.m.c.=2⁴·3²=144

-15/144 + 56/144 - 4/144 - 132/144 = -95/144

e)-17/5 + 43/10 - 34/15 = 

Numitor comun 30

-102/30 + 129/30 - 68/30 = -41/30 = 1 intreg 11/30

*Pentru cine a întrebat :

-3 întregi 2/5 = -17/5

Answer 2

a) (- 7/36) + (- 5/18) + (- 1/24) + (11/48) = 
    (- 27/144) + (- 40/144) + (- 6/144) + 33/144 =
    - 28/144 - 40/144 - 6/144 + 33/144 =
    - 41/144 
b) (- 4/21) + (- 6/7) + (5/42) + (9/14) =
    - 8/42 - 36/42 + 5/42 + 27/42 =
    - 12/42 = - 2/7
c) (3/4) + (- 5/24) + (7/8) + (- 1/16) = 
    36/48 - 10/48 + 42/48 - 3/48 = 
    65/48
d) (- 5/48) + (7/18) + (- 1/36) + (- 11/12) = 
    - 15/144 + 56/144 - 4/144 - 132/144 = 
    - 95/144
e) (- 32/5) - (- 43/10) - (24/15) = 
    - 192/30 + 129/30 - 48/30 = 
    - 111/30 = - 37/10