a: =-5,3*2,1=-11,13

b: =3/4-4/5

=15/20-16/20

=-1/20

19: \(\left(-17\right)+7-10\)

\(=\left(-17+7\right)-10\)

=-10-10

=-20

20: \(\left(-18\right)+10+8\)

\(=\left(-18\right)+\left(10+8\right)\)

=-18+18

=0

21: \(\left(-20\right)+15+5\)

\(=\left(-20\right)+\left(15+5\right)\)

=-20+20

=0

22: \(\left(-16\right)+8+8\)

\(=\left(-16\right)+\left(8+8\right)\)

=-16+16

=0

23: \(\left(-6\right)+3-3\)

\(=\left(-6\right)+\left(3-3\right)\)

=-6+0

=-6

24: \(13+3-16\)

\(=\left(13+3\right)-16\)

=16-16

=0

1: \(\left(-5\right)+8-7=8+\left(-5-7\right)\)

=-12+8

=-4

2: \(\left(-8\right)+2+8=\left(-8+8\right)+2=0+2=2\)

3: \(\left(-1\right)+3+1\)

\(=\left(-1+1\right)+3\)

=0+3

=3

4: \(\left(-6\right)+8-14\)

\(=\left(-6-14\right)+8\)

=-20+8

=-12

5: \(\left(-4\right)+3-7\)

\(=\left(-4-7\right)+3\)

=-11+3

=-8

6: \(\left(-4\right)+5-2\)

\(=\left(-4-2\right)+5\)

=-6+5

=-1

`1,14 . 6,4 + 1,14 . 3,6 + 0,2 . 1,14 . 5`

`= 1,14 . (3,6 + 6,4 + 1)`

`= 1,14 . 11`

`= 12,54`

31: (-29)+8-9

\(=\left(-29\right)+\left(8-9\right)\)

\(=-29-1=-30\)

32: \(\left(-14\right)-6-10\)

\(=\left(-14-6\right)-10\)

=-20-10

=-30

33: \(\left(-42\right)+10+2\)

\(=\left(-42\right)+\left(10+2\right)\)

=-42+12

=-30

34: \(\left(-45\right)+25-20\)

\(=\left(-45\right)+\left(25-20\right)\)

=-45+5

=-40

35: \(\left(-60\right)+17+3\)

\(=\left(-60\right)+\left(17+3\right)\)

=-60+20

=-40

36: \(\left(-48\right)+18-10\)

\(=\left(-48+18\right)-10\)

=-30-10

=-40

câu d) 

\(\dfrac{6}{5}+\left(3+\dfrac{-1}{5}\right)\\ =\dfrac{6}{5}+3+\dfrac{-1}{5}\\ =1+3=4\)

câu e)

\(-\dfrac{3}{5}+\left(-\dfrac{2}{5}+2\right)\\ =\dfrac{-3}{5}+\dfrac{-2}{5}+2\\ =-1+2=1\)

câu f)

\(\dfrac{8}{3}-\left(-\dfrac{4}{3}+3\right)\\ =\dfrac{8}{3}+\dfrac{4}{3}-3\\ =4-3=1\)

Lời giải:
g.

$=\frac{-5}{11}+\frac{-6}{11}+1=(\frac{-5}{11}+\frac{-6}{11})+1$

$=\frac{-11}{11}+1=(-1)+1=0$

h.

$=\frac{-17}{13}+\frac{4}{13}+\frac{25}{101}$

$=\frac{-13}{13}+\frac{25}{101}=(-1)+\frac{25}{101}=-(1-\frac{25}{101})$

$=\frac{-76}{101}$

i.

$=\frac{6}{7}+\frac{1}{8}-\frac{3}{16}.4=\frac{6}{7}+\frac{1}{8}-\frac{3}{4}$

$=\frac{6}{7}+\frac{1}{8}-\frac{6}{8}=\frac{6}{7}+\frac{-5}{8}$
$=\frac{13}{56}$

CÂU A)

\(\dfrac{5}{3}+\left(7+\dfrac{-5}{3}\right)\\ =\dfrac{5}{3}+7+\dfrac{-5}{3}=7\)

CÂI B)

\(-\dfrac{7}{31}+\left(\dfrac{24}{17}+\dfrac{7}{31}\right)\\ =-\dfrac{7}{31}+\dfrac{24}{17}+\dfrac{7}{31}=\dfrac{24}{17}\)

CÂU C)

\(\dfrac{3}{7}+\left(-\dfrac{1}{5}+\dfrac{-3}{7}\right)\\ =\dfrac{3}{7}-\dfrac{1}{5}-\dfrac{3}{7}=-\dfrac{1}{5}\)