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

132.(-99)-132.1

132.(-99-1)

132.(-100)

-13200

k

-132.99-132 = -0,99

132,99-132=0,99

7: \(\left(-2\right)+4-3=\left(-2-3\right)+4=-5+4=-1\)

8: \(\left(-6\right)+5+5=\left(-6\right)+\left(5+5\right)=10-6=4\)

9: \(\left(-2\right)+7+1=\left(-2\right)+\left(7+1\right)=8-2=6\)

10: \(\left(-4\right)+14-10\)

\(=\left(-4-10\right)+14\)

=14-14

=0

11: \(\left(-7\right)+5+2\)

\(=\left(-7\right)+\left(5+2\right)\)

=7-7

=0

12: \(\left(-6\right)+4+2\)

\(=\left(-6\right)+\left(4+2\right)\)

=-6+6

=0

A, =47.(-1).12+12.(-53)

    =(-47).12+12.(-53)

     =[(-47)+(-53)].12

    =-100.12

    =-1200

Thực hiện phép tính (tính nhanh nếu có thể)

a, 47.(-12) + 12. (-53)

=(-47).12+12.(-53)

=12.[-47+(-53)]

=12.(-100)

=-1200

b, 106. (-3 - 105) - 106.(-105)

=106.[-3-105-(-105)]

=106.(-3)

=-318

\(a,47.\left(-12\right)+12.\left(-53\right)\)

\(=47.\left(-1\right).12+12.\left(-53\right)\)

\(=-47.12+12.\left(-53\right)\)

\(=12.\left[-47+\left(-53\right)\right]\)

\(=12.\left(-100\right)=-1200\)

\(b,106.\left(-3-105\right)-106.\left(-105\right)\)

\(=106.\left[-3-105-\left(-105\right)\right]\)

\(=106.\left(-3\right)=-318\)

\(\left(1981\times1982-990\right):\left(1980\times1982+992\right)\)

\(=\left(1980\times1982+1982-990\right):\left(1980\times1982+992\right)\)

\(=\left(1980\times1982+992\right):\left(1980\times1982+992\right)\) 

\(=1\)

Số các số hạng có :

  \(\left(100-2\right):2+1=50\) ( số hạng )

Tổng là :

   \(50\times\left(100+2\right):2=2550\)

    Đáp số : 2550

(100+2) x50 :2= 25 500

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

b: =3/4-4/5

=15/20-16/20

=-1/20

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)

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