trình bày chi tiết với ạ;-;

`@` `\text {Ans}`

`\downarrow`

`1,`

`a)`

`-7/25 + (-8)/25`

`= (-7 - 8)/25`

`= -15/25`

`= -3/5`

`b)`

`6/13 + (-15)/39`

`= 18/39 + (-15)/39`

`= (18 - 15)/39`

`= 3/39`

`= 1/13`

`c)`

`5/7 + 4/(-14)`

`= 10/14 + (-4)/14`

`= (10 - 4)/14`

`= 6/14`

`= 3/7`

`d)`

`-8/18 + (-15)/27`

`= -4/9 + (-5)/9`

`= (-4-5)/9`

`= -9/9 = -1`

`2,`

`a)`

`3/5 + (-7)/4`

`= 12/20 + (-35)/20`

`= (12 - 35)/20`

`=-23/20`

`b)`

`(-2) + (-5)/8`

`= (-16)/8 + (-5)/8`

`= (-16 - 5)/8`

`= -21/8`

`c)`

`1/8 + (-5)/9`

`= 9/72 + (-40)/72`

`= (9-40)/72`

`= -31/72`

`d)`

`6/13 + (-14)/39`

`= 18/39 + (-14)/39`

`= (18 - 14)/39`

`= 4/39`

`e)`

`(-18)/24 + 15/21`

`= (-3)/4 + 5/7`

`= (-21)/28 + 20/28`

`= (-21 + 20)/28`

`= -1/28`

Bài 1: 

a: =25+75=100

b: =60-17-43+12=12

c: =-2-18=-20

d: =-3+36-17=36-20=16

Bài 2: 

a: =-102

b: =-1000

c: =12x15=180

d: =21x(-10)=-210

B1

a 100

b 12

c -20

d 16

B2

a -102

b -1000

c 180

d -210

Bài 1:Tính

 a)(-12)+25+75+12 = 100

b)60+12+(-17)+(-43)=12
c)(-2)+(-87)+(-18)+87=-20
d)(-1)+(-2)+36+(-17)=16
Bài 2:Tính
b)8 . (-125)=-100
c)(-12) . (-15)=180
d)21 . (- 3)+(- 21 ) . 7=-210

a) -17-(8-25)

= -17 - 8 + 25

= -25 + 25 =0

b)(-44)-(-14-30)

= -44 + 14 + 30

= -30 + 30 = 0

a) -17 - (8 - 25)

= -17 - 8 + 25

= -25 + 25

= 0

b) (- 44) - (-14 - 30)

= -44 + 14 + 30

= -30 + 30

= 0

a) -17-(8-25)

= -17 - 8 + 25

= -25 + 25 =0

b)(-44)-(-14-30)

= -44 + 14 + 30

= -30 + 30 = 0

Câu 1: 

a:=17+5=22

b: =40-25=15

a: =367-24+133-76

=500-100

=400

a) 800 : 125 = 6.4

b) 715 : 25 =  28.6         

c) 89 : 35,6 =  2.5

d) 66 : 0,55 = 120

=)

Giúp em với ạ 

a \(\dfrac{3}{2}\)

b \(\dfrac{8}{3}\)

a) \(\dfrac{5}{12}+\dfrac{3}{4}+\dfrac{1}{3}=\dfrac{5}{12}+\dfrac{9}{12}+\dfrac{4}{12}=\dfrac{18}{12}=\dfrac{3}{2}\)

b) \(\dfrac{4}{9}+\dfrac{25}{18}+\dfrac{5}{6}=\dfrac{8}{18}+\dfrac{25}{18}+\dfrac{15}{18}=\dfrac{48}{18}=\dfrac{8}{3}\)