a) \(\dfrac{13}{6}\)b) \(\dfrac{7}{18}\)c) \(5\) d) \(\dfrac{2}{3}\)

1.

a)x\(=\)\(\dfrac{7}{6}\)\(-\dfrac{2}{3}\)

  x\(=\dfrac{1}{2}\)

b)x\(=\dfrac{9}{2}:\dfrac{3}{4}\)

   x\(=6\)

LỘN LỚP GÙI CÁI ĐẤY KIẾN THỨC LỚP 4 MÀ CỤ

a: \(=\dfrac{-3-5-7}{4}=\dfrac{-15}{4}\)

b: \(=\dfrac{-6-5-2+6}{11}=\dfrac{-7}{11}\)

a)-1-2-3-4-5-6-....-80

=(-1)+(-2)+(-3)+(-4)+(-5)+(-6)+...+(-80)

Khoảng cách giữa các số:(-1)-(-2)=1

Tổng các số hạng:(-1)-(-80)+1=80 số

Tổng:[(-1)+(-80)].80:2= -3240

=>-1-2-3-4-5-6+......-80=-3240

b,1-2+3-4+5-6+......+2021-2022

=(1-2)+(3-4)+(5-6)+...+(2021-2022)

=(-1)+(-1)+(-1)+...+(-1)

Tổng số cặp là:

(2022-1+1):2=1011 cặp

-1.1011=-1011

=>1-2+3-4+5-6+......+2021-2022= -1011

c, Đề bài sai

d,-4-8-12-16-.......-2020

=-4+(-8)+(-12)+(-16)+...+(-2020)

Khoảng cách giữa các số:-4-(-8)=4

Tổng các số hạng:[-4-(-2020]:4+1=505 số

Tổng:[-4+(-2020)].505:2=-511060

=>-4-8-12-16-.......-2020=-511060

Mọi người giúp mình với ạ! Thank you everyone!

3/4 x 3/2 = 9/8

3/2 - 1/3 = 7/6

3/4x3/2=9/8

3/2-1/3=7/6

a, = 3/4 x 3/2 = 9/8

b, 3/2 - 1/3 = 7/6 

a) \(\dfrac{-2}{3}+\dfrac{3}{4}=\dfrac{-8}{12}+\dfrac{9}{12}=\dfrac{1}{12}\)

b) \(\dfrac{5}{6}-\dfrac{-3}{5}=\dfrac{5}{6}+\dfrac{3}{5}=\dfrac{25}{30}+\dfrac{18}{30}=\dfrac{43}{30}\)

`a)` \(\dfrac{-2}{3}+\dfrac{3}{4}=\dfrac{-8}{12}+\dfrac{9}{12}=\dfrac{1}{12}\)

`b)` \(\dfrac{5}{6}-\dfrac{-3}{5}=\dfrac{5}{6}+\dfrac{3}{5}=\dfrac{25}{30}+\dfrac{18}{30}=\dfrac{43}{30}\)

a)\(\dfrac{-2}{3}+\dfrac{3}{4}=-\dfrac{8}{12}+\dfrac{9}{12}=\dfrac{1}{12}\)

b)\(\dfrac{5}{6}-\dfrac{-3}{5}=\dfrac{25}{30}-\dfrac{-18}{30}=\dfrac{25}{30}+\dfrac{18}{30}=\dfrac{43}{30}\)

9/15+4/15= 13/15

2/1-7/12= 24/12-7/12= 17/12

10/21

5/6:5/1= 5/6x1/5= 5/30= 1/6

a: \(=\dfrac{5}{9}-\dfrac{12+5}{15}:\dfrac{6}{5}\)

\(=\dfrac{5}{9}-\dfrac{17}{15}\cdot\dfrac{5}{6}=\dfrac{5}{9}-\dfrac{17}{18}=-\dfrac{7}{18}\)

b: \(=\left[\dfrac{6}{5}\left(3+\dfrac{3}{8}-6-\dfrac{5}{8}\right)\right]\cdot\dfrac{5}{6}=-3-\dfrac{1}{4}=-\dfrac{13}{4}\)

a) \(\dfrac{6}{7}+\dfrac{7}{8}=\dfrac{48}{56}+\dfrac{49}{56}=\dfrac{97}{56}\)

b) \(\dfrac{4}{5}-\dfrac{2}{3}=\dfrac{12}{15}-\dfrac{10}{15}=\dfrac{2}{15}\)

c) \(\dfrac{2}{3}.\dfrac{4}{9}=\dfrac{8}{27}\)

d) \(\dfrac{1}{5}:\dfrac{2}{7}=\dfrac{1}{5}.\dfrac{7}{2}=\dfrac{7}{10}\)

a: =48/56+49/56

=97/56

b: =12/15-10/15

=2/15

c: =(2*4)/(3*9)=8/27

d: =1/5*7/2=7/10

` 6/7 + 7/8 = 48/56 + 49/56 = 97/56`

` 4/5 - 2/3 = 12/15 - 10/15 = 2/15`

` 2/3 xx 4/9 = 8/27`

` 1/5 : 2/7 = 1/5 . 7/2 = 7/10`

a: \(\dfrac{1}{8}\cdot\dfrac{4}{5}:\dfrac{3}{5}=\dfrac{1}{10}\cdot\dfrac{5}{3}=\dfrac{1}{2\cdot3}=\dfrac{1}{6}\)

b: \(=\dfrac{8-3}{12}\cdot\dfrac{6}{5}=\dfrac{6}{12}=\dfrac{1}{2}\)

c: \(=\dfrac{24}{35}:\dfrac{32}{35}=\dfrac{3}{4}\)

d: =63/21+15/21-7/21=71/21

a \(\dfrac{1}{8}\times\dfrac{4}{5}\times\dfrac{10}{6}=\dfrac{1}{6}\)

b \(\left(\dfrac{8}{12}-\dfrac{3}{12}\right)\times\dfrac{6}{5}=\dfrac{5}{12}\times\dfrac{6}{5}=\dfrac{1}{2}\)

c \(\dfrac{24}{35}:\dfrac{32}{35}=\dfrac{24}{35}\times\dfrac{35}{32}=\dfrac{3}{4}\)

d \(\dfrac{63}{21}+\dfrac{15}{21}-\dfrac{7}{21}=\dfrac{71}{21}\)

\(a,\left(2^{2007}+2^{2006}\right):2^{2006}=2^{2007}:2^{2006}+2^{2006}:2^{2006}=2+1=3\\ b,\left(3^{2011}+3^{2010}\right):3^{2010}=3^{2011}:3^{2010}+3^{2010}:3^{2010}=3+1=4\\ c,\left(5^{2001}+5^{2000}\right):5^{2000}=5^{2001}:5^{2000}+5^{2000}:5^{2000}=5+1=6\)

Tương tự là d,e,f và kết quả đúng lần lượt là 5,7,8 nha