Question

(-1/4)+(+3/5)+(-1/10)

Answer 1

$( \frac{-1}{4}) + (\frac{+3}{5}) + (\frac{-1}{10})$

$\frac{-1}{4} + \frac{3}{5} - \frac{1}{10}$

$\frac{(-1).(5) + (3).(4) - (1).(2)}{20}$

$\frac{-5 + 12 - 2}{20} \\ \frac{5}{20}$

Answer 2

- 1 + 3 -  1
  4    5   10

mmc (4,5,10) = 20

4,5,10: 2
2,5,5: 2
1,5,5: 5
1,1,1       = 2.2.5 = 4.5 = 20

20: 4 = 5.(-1) = - 5
20: 5 = 4. 3 = 12
20:10 = 2.(-1) = - 2

- 5 + 12 - 2  = - 5 - 2 + 12 = - 7 + 12 =   5
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