Question

1 1/5 - 2 1/2 - 1 1/3

Answer 1

1 1/5 - 2 1/2 - 1 1/3 =

= ( 1 · 5 + 1 ) / 5 - ( 2 · 2 + 1 ) / 2 - ( 1 · 3 + 1 ) / 3

= 6 / 5 - 5 / 2 - 4 / 3

= ( 6 · 6 - 5 · 15 - 4 · 10 ) / 30

= ( 36 - 75 - 40 ) / 30

= ( -39 - 40 ) / 30

= -79 / 30

Answer 2

$1\dfrac{1}{5}-2\dfrac{1}{2}-1\dfrac{1}{3} = \\ \\ = \dfrac{1}{5}-\dfrac{1}{2}-\dfrac{1}{3}+1-2-1 = \\ \\ = \dfrac{1}{5}-\dfrac{1}{2}-\dfrac{1}{3}-2 = \\ \\ =\dfrac{2\cdot 3-3\cdot 5-5\cdot 2 - 2\cdot 2\cdot 3\cdot 5}{2\cdot 3\cdot 5} = \\ \\ = \dfrac{6-15-10-60}{30} = \\ \\ =\boxed{-\dfrac{79}{30}}$