Question

a) \(\dfrac{-7}{10}-\left(\dfrac{-2}{5}\right)\)

b) \(\dfrac{3}{5}-\left(\dfrac{-7}{10}\right)+\dfrac{13}{20}\)

Answer 1

`(-7)/10 - ((-2)/5)`

`=-7/10 + 2/5`

`=-7/10 + 4/10`

`=(-7+4)/10`

`=-3/10`

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`3/5 - ((-7)/10) + 13/20`

`=3/5 + 7/10 + 13/20`

`=12/20 + 14/20 + 13/20`

`=(12+14+13)/20`

`=39/20`

Answer 2

a, -3/10

b, -13/20

Answer 3

\(a,\dfrac{-7}{10}-\left(-\dfrac{2}{5}\right)\)

\(=\dfrac{-7}{10}-\dfrac{-4}{10}\)

\(=\dfrac{\left(-7\right)-\left(-4\right)}{10}=\dfrac{-3}{10}\)

\(b,\dfrac{3}{5}-\left(\dfrac{-7}{10}\right)+\dfrac{13}{20}\)

\(=\dfrac{12}{20}-\dfrac{-14}{20}+\dfrac{13}{20}\)

\(=\dfrac{12-\left(-14\right)+13}{20}=\dfrac{39}{20}\)