Question

Answer 1

-2

Answer 2

1/2-2/5-21/10

=1/10-21/10

=-2

Answer 3

\(=\dfrac{1}{2}-\dfrac{2}{5}-\dfrac{21}{10}=\dfrac{5}{10}-\dfrac{4}{5}-\dfrac{21}{10}=-\dfrac{20}{10}=-2\)

Answer 4

-2

Answer 5

\(\dfrac{1}{2}-\dfrac{2}{5}+\dfrac{-21}{10}=\dfrac{5}{10}-\dfrac{4}{10}+\dfrac{-21}{10}=\dfrac{5-4+\left(-21\right)}{10}=\dfrac{-20}{10}=-2\)

Answer 6

\(\dfrac{1}{2}-\dfrac{2}{5}+\dfrac{-7}{10}\cdot3=\dfrac{1}{2}-\dfrac{2}{5}+\dfrac{-21}{10}=\dfrac{5}{10}-\dfrac{4}{10}+\dfrac{-21}{10}=\dfrac{1}{10}+\dfrac{-21}{10}=\dfrac{-20}{10}=-2\)

Answer 7

\(\dfrac{1}{2}-\dfrac{2}{5}-\dfrac{21}{10}\)

\(=\dfrac{5}{10}-\dfrac{4}{10}-\dfrac{21}{10}=-\dfrac{20}{10}=-2\)

Answer 8

1/2-2/5-21/10

=1/10-21/10

=-2