c=1+2-3-4+5+6-7-.......+2014-2015-2016+2017+2018

c=-4+-4+.....+-4+-4+2018

C=(-4).1009+2018\

C=-4036+2018

c=-2018

Đoàn Việt Hoàng ơi hình như bn làm sai rồi bn xem lại đi nha.Nếu bn đúng thì cho mk xin lỗi.

đúng r bạn

1) 

a) - 37 + 54 + (- 70) + (-163) + 246

= (-37 + (-163)) + (54 + 246) + (-163)

= -200 + 300 + (- 163)

= 100 + (-163)

= - 63

b) 125. (-61) . 2³. (-1)²ⁿ

= (125 . 2³) . (-61) . 1

= 1000 . (- 61)

= - 6100

c) mk không biết làm nha

a)-37+54+-70+-163+246

=[(-370 + (-70)+(-163)]+(54 + 246)

=(-603)+300

=-303

c)1+2-3-4+5+6 -7....+2014-2015-2016+2017+2018

=-4+-4+......+-4+2018

=(-4).505+2018

=-2020+2018

=-2

A)\(\dfrac{7}{20}-\left(\dfrac{5}{8}-\dfrac{2}{5}\right)\)

\(=\dfrac{7}{20}-\left(\dfrac{25}{40}-\dfrac{16}{40}\right)\)

\(=\dfrac{7}{20}-\dfrac{9}{40}\)

\(=\dfrac{14}{40}-\dfrac{9}{40}=\dfrac{5}{40}=\dfrac{1}{8}\)

B) \(\dfrac{5}{6}+\left(\dfrac{5}{9}-\dfrac{1}{4}\right)\)

\(=\dfrac{5}{6}+\left(\dfrac{20}{36}-\dfrac{9}{36}\right)\)

\(=\dfrac{5}{6}+\dfrac{11}{36}\).

\(=\dfrac{30}{36}+\dfrac{11}{36}=\dfrac{41}{36}\)

C) \(\dfrac{9}{10}-\left(\dfrac{2}{5}-\dfrac{3}{10}\right)+\dfrac{7}{20}\)

\(=\dfrac{9}{10}-\left(\dfrac{4}{10}-\dfrac{3}{10}\right)+\dfrac{7}{20}\)

\(=\dfrac{9}{10}-\dfrac{1}{10}+\dfrac{7}{20}\)

\(=\dfrac{18}{20}-\dfrac{2}{20}+\dfrac{7}{20}=\dfrac{23}{20}\)

a: =7/20-5/8+2/5

=14/40-25/40+16/40

=5/40=1/8

b: =5/6+5/9-1/4

=30/36+20/36-9/36

=41/36

c: =9/10-2/5+3/10+7/20

=12/10-2/5+7/20

=7/20+6/5-2/5

=7/20+4/5

=7/20+16/20

=23/20

https://olm.vn/hoi-dap/detail/104380939254.html?pos=228315034049

bạn coi thử nha

Ta có:

A = -1 – 2 + 3 + 4 – 5 – 6 + 7 + 8 – 9 – 10 + 11 + 12 - ... – 2013 – 2014 + 2015 + 2016

A = (0 – 1 – 2 + 3) + (4 – 5 – 6 + 7) + ... + (2012-  2013 – 2014 + 2015) + 2016

A = 0 + 0 + ... + 0

A = 2016

Vậy A = 2016

#Mạt Mạt#

Trả lời:

= 2016 nha~ =w=

Hok tốt!

a) 5^2018:2^2015-6^2+2017^0

=5^3-36+1

=125-36+1

=89+1=90

b)12:{390:[500-(5^3+35.7)]}

=12:{390:[500-(125+245)]}

=12:{390:[500-370]}

=12:{390:130}

=12:3=4

Hok tốt 

Là sao!!!!!???????!!!!!???

=1019596

Hình như nó sai ấy bn nha

sr nham

ta co:

(de bai)=(1-3)+(5-7)+(9-11)+...+(2017-2019)=(-2)*505=-1010

`a, 3/4 + 1/2 xx 7/2`

`= 3/4 + 7/4`

`=10/4`

`=5/2`

`b, 6/15 - 1/3 : 5/3`

`= 6/15 - 1/3 xx 3/5`

`= 6/15 - 3/15`

`= 3/15`

`=1/5`

`c, x-4/9 = 3/7 : 9/4`

`=> x-4/9= 3/7 xx 4/9`

`=> x-4/9= 12/63`

`=> x-4/9=4/21`

`=> x= 4/21 +4/9`

`=>x= 40/63`

`d, 7/9 xx 3/5 -1/2=1/5`

`->` sao lại bằng có `x` ko vậy ạ?

`a,`

`3/4+1/2 \times 7/2=3/4+7/4=10/4=5/2`

`b,`

`6/15 - 1/3 \div 5/3=6/15-1/5=1/5`

`c,` Tìm x?

`x-4/9=3/7 \div 9/4`

`x-4/9=4/21`

`x=4/21+4/9`

`x=40/63`

`d, 7/9x \times 3/5-1/2=1/5`

`7/9x \times 3/5=1/5+1/2`

`7/9x \times 3/5=7/10`

`7/9x=7/10 \div 3/5`

`7/9x=7/6`

`x=7/6 \div 7/9=3/2`