K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

26 tháng 6 2018

a, x + \(2\frac{3}{4}\)\(5\frac{2}{3}\)

= x + \(\frac{11}{4}\)\(\frac{17}{3}\)

x = \(\frac{17}{3}\)\(\frac{11}{4}\)

x = \(\frac{35}{12}\)

b , x - \(1\frac{4}{5}\)\(3\frac{2}{7}\)

 = x - \(\frac{9}{5}\)\(\frac{23}{7}\)

x = \(\frac{23}{7}\)\(\frac{9}{5}\)

x = \(\frac{178}{35}\)

c , x * \(\frac{31}{2}\)\(4\frac{3}{4}\)

= x * \(\frac{31}{2}\)=\(\frac{19}{4}\)

x = \(\frac{19}{4}\)\(\frac{31}{2}\)

x = \(\frac{38}{124}\)\(\frac{19}{64}\)

d , x : 2 2/? = 4 1/3 câu d thiếu nha bạn 

21 tháng 2 2023

` 8/23 . 46/24 =1/3 .x`

`=>8/23 . 23/12 =1/3 . x`

`=> 1/3 . x=2/3`

`=>x=2/3 : 1/3`

`=>x=2/3 . 3`

`=> x= 6/3`

`=>x=2`

`----`

`1/5 : x= 1/5-1/7`

`=>1/5 : x=  7/35 - 5/35`

`=> 1/5 :x= 2/35`

`=>x= 1/5 : 2/35`

`=>x=1/5 . 35/2`

`=>x=7/2`

`----`

`4/9 - (x-1/2)^2 =1/3`

`=> (x-1/2)^2 =4/9-1/3`

`=> (x-1/2)^2 =4/9- 3/9`

`=> (x-1/2)^2 =1/9`

`=> (x-1/2)^2 = (+- 1/3)^2`

`@ TH1`

`x-1/2=1/3`

`=>x=1/3+1/2`

`=>x= 2/6 + 3/6`

``=>x= 5/6`

`@ TH2`

`x-1/2=-1/3`

`=>x=-1/3 +1/2`

`=>x= -2/6 + 3/6`

`=>x=1/6`

`----`

`3,2 . x-(4/5+2/3) : 3 2/3 = 7/10`

`=> 3,2 . x-22/15 : 11/3 = 7/10`

`=>  3,2 . x-22/15 = 7/10 . 11/3`

`=>  3,2 . x-22/15 =77/30`

`=> 3,2 .x= 77/30 + 22/15`

`=> 3,2 .x=121/30`

`=>x= 121/30. 5/16`

`=>x= 121/96`

6 tháng 8 2019

1a) -3x2(2x3 - 2x + 1/3) = -6x5 + 6x3 - x2

b) (x4 + 2x3 - 2/3).(-3x4) = -3x8 - 6x7 + 2x4

c) (x + 3)(x - 4) = x2 - 4x + 3x - 12 = x2 - x - 12

d)(x - 4)(x2 + 4x + 16) = (x - 4)(x2 + 4x + 42) = x3 - 64

e) 4(x - 1/2)(x + 1/2)(4x2 + 1) =4(x2 - 1/4)(4x2  + 1) = 4(4x4 + x2 - x2 - 1/4) = 4(4x4 - 1/4) = 16x4 - 1

B2. a) (2 - x)(x2 + 2x + 4) + x(x - 3)(x + 4) - x2 + 24 = 0

=> 8 - x3 + x(x2 + 4x - 3x - 12) - x2 + 24 = 0

=> 8 - x3 + x3 + x2 - 12x - x2 + 24 = 0

=> -12x + 32 = 0

=> -12x = -32

=> x = -32 : (-12) = 8/3

b) (x/2 + 3)(5 - 6x) + (12x - 2)(x/4 + 3) = 0

=> 5x/2 - 3x2 + 15 - 18x + 3x2 + 36x - x/2 - 6 = 0

=> 20x + 9 = 0

=> 20x = -9

=> x = -9/20

8 tháng 12 2021

a) \(\dfrac{x+5}{4}-\dfrac{x}{2}+1=0\)

<=> \(\dfrac{x+5-2x+4}{4}=0\)

<=> -x + 9 = 0 <=> x = 9

b) \(3\left(x+2\right)=\dfrac{x-4}{3}\)

<=> 9x + 18 = x-4

<=> 8x = -22

<=> x = \(\dfrac{-11}{4}\)

29 tháng 8 2021

\(a,x+\dfrac{2}{5}=\dfrac{1}{2}\)

\(x=\dfrac{1}{2}-\dfrac{2}{5}\)

\(x=\dfrac{5}{10}-\dfrac{4}{10}\)

\(\Rightarrow x=....\)

 

 

29 tháng 8 2021

\(a,x+\dfrac{2}{5}=\dfrac{1}{2}\\ \Rightarrow x=\dfrac{1}{2}-\dfrac{2}{5}=\dfrac{5-4}{10}=\dfrac{1}{10}\)

\(b,x-\dfrac{2}{5}=\dfrac{1}{7}\\ \Rightarrow x=\dfrac{1}{7}+\dfrac{2}{5}=\dfrac{5+14}{35}=\dfrac{19}{35}\)

\(c,x\cdot\dfrac{3}{4}=\dfrac{9}{20}\\ \Rightarrow x=\dfrac{9}{20}:\dfrac{3}{4}=\dfrac{9}{20}\cdot\dfrac{4}{3}=\dfrac{3\cdot1}{5\cdot1}=\dfrac{3}{5}\)

\(d,x:\dfrac{1}{7}=14\\ \Rightarrow x=14\cdot\dfrac{1}{7}=\dfrac{14}{7}=2\)

\(e,\dfrac{2}{3}-x=\dfrac{1}{5}\\ \Rightarrow x=\dfrac{2}{3}-\dfrac{1}{5}=\dfrac{10-3}{15}=\dfrac{7}{15}\)

\(f,\dfrac{4}{15}:x=\dfrac{12}{25}\\ \Rightarrow x=\dfrac{4}{15}:\dfrac{12}{25}=\dfrac{4}{15}\cdot\dfrac{25}{12}=\dfrac{1\cdot5}{3\cdot3}=\dfrac{5}{9}\)

 

NV
18 tháng 4 2021

1.

\(y'=12x+\dfrac{4}{x^2}\)

2.

\(y'=\dfrac{3}{\left(-x+1\right)^2}\)

3.

\(y'=\dfrac{2x-3}{2\sqrt{x^2-3x+4}}\)

4.

\(y=\dfrac{x^3+3x^2-x-3}{x-4}\)

\(y'=\dfrac{\left(3x^2+6x-1\right)\left(x-4\right)-\left(x^3+3x^2-x-3\right)}{\left(x-4\right)^2}=\dfrac{2x^3-9x^2-24x+7}{\left(x-4\right)^2}\)

5.

\(y'=-\dfrac{4x-3}{\left(2x^2-3x+5\right)^2}\)

6.

\(y'=\sqrt{x^2-1}+\dfrac{x\left(x+1\right)}{\sqrt{x^2-1}}\)

a: x*3/4=1/5

=>x=1/5:3/4=1/5*4/3=4/15

b: x*3/7=2/5

=>x=2/5:3/7=2/5*7/3=14/15

c: 1/3+2/9=2/12x

=>1/6x=3/9+2/9=5/9

=>x=5/9*6=30/9=10/3

d: 4/15*x-2/3=1/5

=>4/15*x=2/3+1/5=10/15+3/15=13/15

=>4x=13

=>x=13/4

e: x:1/7=2/3

=>x=2/3*1/7=2/21

f: 1/9:x=7/3

=>x=1/9:7/3=1/9*3/7=3/63=1/21

j: 1/4+5/12=8/3:x

=>8/3:x=3/12+5/12=8/12=2/3

=>x=4

h: =>7/4:x=1/5+1/2=7/10

=>x=7/4:7/10=10/4=5/2

30 tháng 8 2023

thankkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk