(2,5-2 1/3)*(-5 1/7)+1 1/3:(-5,6)=

(2,5 - 2 1/3) · (-5 1/7) + 1 1/3 : (-5,6) = (-1 целая 2/21)

1) 2,5 - 2 1/3 = 5/2 - 7/3 = 15/6 - 14/6 = 1/6

2) 1/6 · (-5 1/7) = 1/6 · (-36/7) = - (1·6)/(1·7) = (-6/7)

3) 1 1/3 : (-5,6) = 4/3 : (-28/5) = 4/3 · (-5/28) = - (1·5)/(3·7) = (-5/21)

4) (-6/7) + (-5/21) = - (18/21 + 5/21) = (-23/21) = (- 1 2/21)

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Пояснения:

2,5 = 25/10 = 5/2 - сократили на 5

5,6 = 56/10 = 28/5 - сократили на 2

(2,5-2 1/3)*(-5 1/7)+1 1/3:(-5,6)=-(23/21)=-1(2/21)1) 2,5-2(1/3)=(25/10)-(7/3)=(5/2)-(7/3)=(5×3-7×2)/6=(1/6)2) (1/6)×(-(5(1/7)))=-(1/6)×(36/7)=-(1×6×6)/(6×7)=-(6/7)3) 1(1/3)÷(-5,6)=-(4/3)×(10/56)=-(4×5×2)/(3×4×7×2)=-(5/21)4) -(6/7)+(-(5/21))=-(6/7)-(5/21)=-((6×3+5)/21)=-(23/21)=-1(2/21)