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5/2 đó k chị nhé

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5/2 k cho mình nha

phan AVIET DAY so them mot it di

Ta có:

A = 1 + 3 + 5 + 7 +... + 101

A = \(\frac{102.51}{2}=2601\)

M = 16 - 18 + 20 - 22 + 24 - 26 + .. + 64 - 66 + 68

M = ( 16 - 18 ) + ( 20 - 22 ) + ( 24 - 26 ) + ... + ( 64 - 66 ) + 68

M = (- 2 + - 2 + -2  + ... + - 2 ) + 68

M = 25/2 . ( - 2 ) + 68

M = -25 + 68

M = 43

H = ( 1 + 2 + 3 +...+ 99 ) x ( 13 x 15 - 12 x 15 - 15 )

H = ( 1 + 2 + 3 +...+ 99 ) x { (13 - 12 - 1) x 15 }

H = ( 1 + 2 + 3 +...+ 99 ) x 0

H = 0

G = 1 + 2 - 3 - 4 + 5 + 6 - 7 - 8 + 9 + 10 - 11 - 12 + 13 + 14 - ... + 301 + 302

G = ( 1 + 2 ) + ( -3 - 4 ) + ( 5 + 6 ) + ( -7 - 8 ) + ( 9 + 10 ) + ( - 11 - 12 ) + ( 13 + 14 ) -...+ ( 301 + 302 )

G = ( 3 - 7 ) + ( 11 - 15 ) + ( 19 - 23 ) + 27 - ... + 603

G = -4 + - 4 + -4 + 27 - ... + 603

G = 75 x ( -4 ) + 603

G = -300 + 603

G = 303

2.

a) 1 + 2 + 3 + 4 +...+ 99 + 100 + 2 x X = 5052

= > \(\frac{100.101}{2}\)+ 2 x X = 5052

= > 5050 + 2 x X = 5052

= > 2X = 2

= > X = 1

bui thi huyen chi nào vậy

Ai đấy tôi ko biết

Trên đời có mỗi tui Là Bùi Thị Huyền Chi thoy

Ko có ng thứ 2 đâu

(10/99 +11/199 -12/299).(1/2-1/3+-1/6)

=(10/99 +11/199 -12/299).0

=0

HOK TỐT

Đề bài: (10/99+11/199-12/299).(1/2-1/3+ -1/6)

=(10/99+11/199-12/299).(3/6-2/6+ -1/6)

=(10/99+11/199-12/299).(3-2+ -1/6)

=(10/99+11/199-12/299).0

=0.

Hok tốt nhé !

\(\left(\frac{10}{99}+\frac{11}{199}-\frac{12}{299}\right).\left(\frac{1}{2}-\frac{1}{3}+\frac{-1}{6}\right)\)

\(=\left(\frac{10}{99}+\frac{11}{199}-\frac{12}{299}\right).0\)

\(=0\)

~ Hok tốt ~

S = [ 1+(-3)] + [5+(-7)] +........+[2001+(-2003)] +2005   vì có  ( 2005-1):2+1 = 1003 số hạng của tổng  nên số cặp là 1002:2 =501

   =  (-2)        +  (-2)    + .........+    (-2)           + 2005                          ;   có 501 số (-2)

  = 501.(-2)  +2005

=-1002 + 2005 = 1003

31/17+(-5/13)+(-8/13)-14/17

=(31/17-14/17)+[-5/13+(-8/13)]

=1+(-1)

=0

\(\frac{31}{17}+\frac{-5}{13}+\frac{-8}{13}-\frac{14}{17}\)

\(=\left[\frac{31}{17}-\frac{14}{17}\right]+\left[\frac{-5}{13}+\frac{-8}{13}\right]\)

\(=1+(-1)=0\)

\(\frac{31}{17}+\frac{-5}{13}+\frac{-8}{13}-\frac{14}{17}\)

\(=\left(\frac{31}{17}-\frac{14}{17}\right)+\left(\frac{-5}{13}+\frac{-8}{13}\right)\)

\(=1+\left(-1\right)\)

\(=0\)

~ Hok tốt ~

\(=\dfrac{1}{3}+\dfrac{1}{4}+\dfrac{1}{5}+\dfrac{4}{5}+\dfrac{2}{3}+\dfrac{1}{4}\)

=(1/3+2/3)+(1/4+1/4)+(1/5+4/5)

=1+1+1/2

=5/2

\(\dfrac{5}{2}\)

a)13-|-2|*|-3|=13-2*3=13-6=7

b)(-469)+(-15)=-484

c)|-3+1|+|-1+3|+|-3+(-1)|=|-2|+|2|+|-4|=2+2+4=8

\(\frac{3}{4}+\frac{1}{4}\cdot x+x-\frac{7}{6}\cdot x=\frac{5}{12}\)

\(\frac{3}{4}+\frac{1}{4}\cdot x-\frac{7}{6}\cdot x+x\cdot1=\frac{5}{12}\)

\(\frac{3}{4}+x\left(\frac{1}{4}-\frac{7}{6}+1\right)=\frac{5}{12}\)

\(\frac{3}{4}+x\cdot\frac{1}{12}=\frac{5}{12}\)

\(x\cdot\frac{1}{12}=\frac{5}{12}-\frac{3}{4}\)

\(x\cdot\frac{1}{12}=\frac{5}{12}-\frac{9}{12}\)

\(x\cdot\frac{1}{12}=\frac{-1}{3}\)

\(x=\frac{-1}{3}\text{ : }\frac{1}{12}\)

\(x=\frac{-1}{3}\cdot12\)

\(x=\frac{-12}{3}\)

\(x=-4\)

\(\text{b, }0,25\cdot x-\frac{2}{3}\cdot x=-1\frac{1}{6}\)

\(\frac{1}{4}\cdot x-\frac{2}{3}\cdot x=\frac{-7}{6}\)

\(x\cdot\left(\frac{1}{4}-\frac{2}{3}\right)=\frac{-7}{6}\)

\(x\cdot\frac{-5}{12}=\frac{-7}{6}\)

\(x=\frac{-7}{6}\text{ : }\frac{-5}{12}\)

\(x=\frac{-7}{6}\cdot\frac{12}{-5}\)

\(x=\frac{-14}{-5}\)

A= 1/2 + 1/4+ 1/8+ 1/16 + 1/32 + 1/64 + 1/128 + 1/256 + 1/512 
A = 1 - 1/2 + 1/2- 1/4 + 1/4 - 1/8 + 1/8 - 1/16 + 1/16 - 1/32 + 1/32 - 1/64 + 1/64 - 1/128 + 1/128 - 1/256 - 1/256 - 1/512 
A = 1 - 1/512 

Ủng hộ mk nha! ^_^