3/2+5/4+9/8/+17/16+33/32-6+x-1/x+1=31/32-2/2015

=(1+1/2)+(1+1/4)+(1+1/8)+(1+1/16)+(1+1/32-6+x-1/x+1=31/32-2/2015

=(1/2+1/4+1/8+1/16+1/32)+(1+1+1+1+1)-6+x-1/x+1=31/32-2/2015

=31/32+5-6+x-1/x+1=31/32-2/2015

=5-6+x-1/x+1=31/32-2/2015-31/32

=-1+x-1/x+1=-2/2015

=x-1/x+1=-2/2015- -1

=x-1/x+1=2013/2015

=>x=2014

đề bài là làm gì vậy bạn?

Tính m x n nhé bạn

\(x=\left(\frac{33}{5}:6-0,125\cdot8+\frac{32}{15}\cdot0,03\right)\cdot\frac{11}{4}\)

\(x=\left(\frac{33}{5}\cdot\frac{1}{6}-\frac{1}{8}\cdot8+\frac{32}{15}\cdot\frac{3}{100}\right)\cdot\frac{11}{4}\)

\(x=\left(\frac{11}{10}-1+\frac{8}{125}\right)\cdot\frac{11}{4}\)

\(x=\frac{41}{250}\cdot\frac{11}{4}\)

\(x=\frac{451}{100}\)

\(x=\left(\frac{33}{5}:6-0,125.8+\frac{32}{15}.0,03\right).\frac{11}{4}\)

\(< =>x=\left(\frac{33}{30}-1+\frac{32}{15}.\frac{3}{100}\right).\frac{11}{4}\)

\(< =>x=\left(\frac{3}{30}+\frac{32}{500}\right).\frac{11}{4}\)

\(< =>x=\left(\frac{1}{10}+\frac{8}{125}\right).\frac{11}{4}\)

\(< =>x=\frac{41}{250}.\frac{11}{4}=\frac{451}{100}\)

x=(11/10-2+8/125)×11/4

x=(-9/10+8/125)×11/4

x=-209/250×11/4

x=-2299/1000

1.\(\dfrac{8}{11}+\dfrac{8}{33}\times\dfrac{3}{4}=\dfrac{8}{11}+\dfrac{8\times3}{33\times4}=\dfrac{8\times12}{11\times12}+\dfrac{8\times3}{33\times4}=\dfrac{8\times15}{132}=\dfrac{120}{132}=\dfrac{10}{11}\)

2.\(\dfrac{7}{9}\times\dfrac{3}{14}:\dfrac{5}{8}=\dfrac{7}{9}\times\dfrac{3}{14}\times\dfrac{8}{5}=\dfrac{4}{15}\)

3.\(\dfrac{5}{12}-\dfrac{7}{32}:\dfrac{21}{16}=\dfrac{5}{12}-\dfrac{7}{32}\times\dfrac{16}{21}=\dfrac{5}{12}-\dfrac{1}{6}=\dfrac{5-2}{12}=\dfrac{3}{12}=\dfrac{1}{4}\)

`@V.Tr.V`

`8/11+8/33xx3/4=8/11+2/11=10/11`

`7/9xx3/14:5/8=7/9xx3/14xx8/5=[7xx3xx4xx2]/[3xx3xx7xx2xx5]=4/[3xx5]=4/15`

`5/12-7/32:21/16=5/12-7/32xx16/21=5/12-2/12=3/12=1/4`

8/11 + 8/33 x 3/4 = 8/11 + 2/11 = 10/11

7/9 x 3/14 : 5/8 = 1/6 : 5/8 = 4/15

5/12 - 7/32 : 21/16 = 5/12 - 1/6 = 1/4

1, \(x=-\dfrac{7}{3}-\dfrac{1}{3}=-\dfrac{8}{3}\)

2, \(x=\dfrac{1}{8}-\dfrac{3}{8}=-\dfrac{2}{8}=-\dfrac{1}{4}\)

3, \(x=\dfrac{6}{5}+\dfrac{4}{5}=\dfrac{10}{5}=2\)

4, \(x=\dfrac{7}{3}-\dfrac{2}{3}=\dfrac{5}{3}\)

5, \(x+\dfrac{7}{3}=\dfrac{5}{3}\Leftrightarrow x=\dfrac{5}{3}-\dfrac{7}{3}=-\dfrac{2}{3}\)

\(=x+\dfrac{1}{3}=\dfrac{-7}{3}\Leftrightarrow x=\dfrac{-8}{3}\)

\(=\dfrac{1}{8}-x=\dfrac{3}{8}\Leftrightarrow x=\dfrac{-1}{4}\)

\(=x-\dfrac{4}{5}=\dfrac{6}{5}\Leftrightarrow x=2\)

\(=\dfrac{2}{3}+x=\dfrac{7}{3}\Leftrightarrow x=\dfrac{5}{3}\)

\(=x-\dfrac{-7}{3}=\dfrac{5}{3}\Leftrightarrow x=\dfrac{-2}{3}\)

1)x=-7/3-1/3

   x=-8/3

2)x=1/8-3/8

   x=-1/4

3)x=6/5+4/5

   x=2

4)x=7/3-2/3

   x=5/3

5)x=5/3+(-7/3)

   x=-2/3

30.31.32.33.A=864y3040

=>(3.3)(10.31.32.11).A=864y3040

=>9.(10.31.32.11).A=864y3040

=>864y3040 chia hết cho 9

=>8+6+4+y+3+0+4+0=25+y chia hết cho 9

=>y=2

ta có:86423040=30.31.32.33.88

vậy y=2

30 = 3 x 10

33 = 3 x 11

Tích trên có thể phân tích có 2 thừa số 3 =>  chia hết cho 9

Vậy y cần tìm là chữ số 2

bổ sung nè :

30 = 3 x 10

33 = 3 x 11

Tích trên có thể phân tích có 2 thừa số 3 =>  chia hết cho 9

=> 8+6+4 +y +3+0+4+0 chia hết cho 9 => 25+y chia hết cho 9

Vậy y cần tìm là chữ số 2

M~~1/4

M=1/4

mk làm bài tính nhanh nha:

k/c dãy số là: 4-2=2

số các số hạng của dãy là: (16-2) : 2 + 1 = 8 ( số)

tổng dãy là: (16+2) * 8 : 2=72

 Đ/S: 72

còn lại tượng tự nha. mk ko bt làm X dãy số thì bn dựa vào nha! NHớ đó

Bài 1:

(x+5).(2x+1) = 0

=> x + 5 = 0 => x = -5

2x + 1 = 0 =>2x = -1 => x = -1/2

KL:...

Bài 2:

a) 2 + 4 + 6 + 8 + 10 + ... + 16

= 2.1+2.2+2.3 +2.4+2.5 +...+2.8

= 2.(1+2+3+4+5+...+8)

= 2. [(1+8).8 : 2]

= 2. 9.8:2

= 9.8

= 72

b) 2.31.12 + 4.6.42 + 8.27.3

= 24.31+24.42 + 24.27

= 24.(31+42+27)

= 24.100

= 2400

c) 26+27+28+...+33

= (33+26).8 : 2

= 59.4

= 236

2x + 5 = 3³ : 3² + 2³.2²

2x + 5 = 3 + 2⁵

2x + 5 = 3 + 32

2x + 5 = 35

2x = 35 - 5

2x = 30

x = 30 : 2

x = 15