Question

3 4/5 - 6 6/10 - 4 4/20

Answer 1

$frac{19}{5} - frac{66}{10} - frac{84}{20} = frac{76}{20} - frac{132}{20} - frac{84}{20} = - frac{140}{20} = -7$

Answer 2

3 4/5 - 6 6/10- 4 4/20= 
3 4/5 - ( 6 6/10 + 4 4/20)=
3 4/5 - (6 12/20 + 4 4/20)=
3 4/5 -10 16/20=
3 4/5 - 10 4/5=
- ( 10 4/5 - 3 4/5)=-7

Ответ : -7