\(a,\left(-5\right)+11+\left(-15\right)+21+\left(-25\right)+31+...+\left(-95\right)+101\\ =\left[\left(-5\right)+11\right]+\left[\left(-15\right)+21\right]+\left[\left(-25\right)+31\right]+...+\left[\left(-95\right)+101\right]\\ =6+6+6+...+6\left(10\text{ số }6\right)\\ =6\cdot10\\ =60\)

\(b,3+\left(-12\right)+13+\left(-22\right)+23+\left(-32\right)+...+93+\left(-102\right)\\ =\left[3+\left(-12\right)\right]+\left[13+\left(-22\right)\right]+\left[23+\left(-32\right)\right]+...+\left[93+\left(-102\right)\right]\\ =\left(-9\right)+\left(-9\right)+\left(-9\right)+...+\left(-9\right)\left(10\text{ số }-9\right)\\ =\left(-9\right)\cdot10\\ =-90\)

\(a,\left(-5\right)+11+\left(-15\right)+21+\left(-25\right)+31+...+\left(-95\right)+101\)

\(=\left[\left(-5\right)+11\right]+\left[\left(-15\right)+21\right]+\left[\left(-25\right)+31\right]+...+\left[\left(-95\right)+101\right]\)

\(=6+6+6+...+6\) (10 số 6)

\(=6.10=60\)

\(\)

Ta có :

3 + ( - 12 ) + 13 + ( -22 ) + ..........+ 93 + ( - 102 )

= [ 3 + ( -12 ) ] + [ 13 + ( -22 ) ] + ... + [ 93 + ( -102 ) ]

= -9 + ( -9 ) + .... + ( -9 )

= ( -9 ) . 10

= -90

ai tra loi nhanh va dung minh se k cho

Bài 3 : a) 3784 + 23 - 3785 - 15

= (3784 - 3785) + (23 - 15)

= -1 + 8 

= 7

b) 21 + 22 + 23 + 24 - 11 - 12 - 13 - 14

= (21 - 11) + (22 - 12) + (23 - 13) + (24 - 14)

= 10 + 10 + 10 + 10 

= 40

Bài 4 : a) -2001 + (1999 + 2001)

= -2001 + 1999 + 2001

= ( - 2001 + 2001 ) + 1999

= 0 + 1999

= 1999

B) (43 - 863) - (137 - 57)

= 43 - 863 - 137 - 57 

= (43 - 57) + ( -863 - 137 )

= -14 + -1000

= -1014 

Nhớ tick !!!

bài 3 

a.=22

b.=40

bài 4:

a.=1999

b.=-900

a. (+18) + (+2)= 20

b. (-3)+13= 11

c. (-12)+(-21)=-33

d. (-30)+(-23)=-53

e. -52+102=50

f. 88+(-23)=65

g. 13+|-13|=26

h. -43-26=-69

k. (-89)-9=-98

m. -56+|-32|=-24

n. 40 -|-14|=26

o. |-4|+|+15|=19

p. |30|-|-17|=13

Lời giải:

\(B=(1.2)^2+(2.2)^2+(3.2)^2+...+(10.2)^2\)

\(=2^2.1^2+2^2.2^2+2^2.3^2+...+2^2.10^2=2^2(1^2+2^2+...+10^2)\)

\(=4A=4.385=1540\)