K
Khách

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

9 tháng 1 2016

|-x + 2| = 4

-x + 2 = 4 => -x = 2 => x = -2

-x + 2 = -4 => -x = -6 => x = 6

Vậy x thuộc {-2 ; 6} 

9 tháng 1 2016

/-x+2/=4

x+2=4=>x=2

x+2=-4=>x=-6

Vì x là số - nên x=-6

 

a: =>x-2/5=3/4:1/3=3/4*3=9/4

=>x=9/4+2/5=45/20+8/20=53/20

b: =>x-2/3=7/3:4/5=7/3*5/4=35/12

=>x=35/12+2/3=43/12

c: 1/3(x-2/5)=4/5

=>x-2/5=4/5*3=12/5

=>x=12/5+2/5=14/5

d: =>2/3x-1/3-1/4x+1/10=7/3

=>5/12x-7/30=7/3

=>5/12x=7/3+7/30=77/30

=>x=77/30:5/12=154/25

e: \(\Leftrightarrow x\cdot\dfrac{3}{7}-\dfrac{2}{7}+\dfrac{1}{2}-\dfrac{5}{4}x+\dfrac{5}{2}=0\)

=>\(x\cdot\dfrac{-23}{28}=\dfrac{2}{7}-3=\dfrac{-19}{7}\)

=>x=19/7:23/28=76/23

f: =>1/2x-3/2+1/3x-4/3+1/4x-5/4=1/5

=>13/12x=1/5+3/2+4/3+5/4=257/60

=>x=257/65

i: =>x^2-2/5x-x^2-2x+11/4=4/3

=>-12/5x=4/3-11/4=-17/12

=>x=17/12:12/5=85/144

a: =16-2+91=14+91=105

b: =9*5+8*10-27=45+53=98

c: =32+65-3*8=8+65=73

d; \(=5^3-10^2=125-100=25\)

e: \(=4^2-3^2+1=8\)

f: =9*16-16*8-8+16*4

=16(9-8+4)-8

=16*5-8

=72

7 tháng 7 2023

a) \(2^4-50:25+13\cdot7\)

\(=2^4-2+91\)

\(=16-2+91\)

\(=14+91\)

\(=105\)

b) \(3^2\cdot5+2^3\cdot10-3^4:3\)

\(=9\cdot5+8\cdot10-3^3\)

\(=45+80-27\)

\(=98\)

c) \(2^5+5\cdot13-3\cdot2^3\)

\(=32+65-3\cdot8\)

\(=32+65-24\)

\(=73\)

d) \(5^{13}:5^{10}-5^2\cdot2^2\)

\(=5^{13-10}-\left(5\cdot2\right)^2\)

\(=5^3-10^2\)

\(=125-100\)

\(=25\)

e) \(4^5:4^3-3^9:3^7+5^0\)

\(=4^{5-3}-3^{9-7}+1\)

\(=4^2-3^2+1\)

\(=16-9+1\)

\(=8\)

f) \(3^2\cdot2^4-2^3\cdot4^2-2^3\cdot5^0+4^2\cdot2^2\)

\(=3^2\cdot4^2-2^3\cdot4^2-2^3\cdot1+4^2\cdot2^2\)

\(=4^2\cdot\left(3^2-2^3+2^2\right)-2^3\)

\(=4^2\cdot\left(9-8+4\right)-8\)

\(=16\cdot5-8\)

\(=72\)

2 tháng 11 2023

\(4^{x+2}-5\cdot4^x=176\)

\(\Rightarrow4^x\cdot4^2-5\cdot4^x=176\)

\(\Rightarrow4^x\cdot\left(16-5\right)=176\)

\(\Rightarrow4^x\cdot11=176\)

\(\Rightarrow4^x=\dfrac{176}{11}\)

\(\Rightarrow4^x=16\)

\(\Rightarrow4^x=4^2\)

\(\Rightarrow x=2\)

2 tháng 11 2023

\(4^{x+2}-5.4^x=176\)

\(=>4^x.4^2-5.4^x=176\)

\(=>4^x.\left(4^2-5\right)=176\)

\(=>4^x.\left(16-5\right)=176\)

\(=>4^x.11=176\)

\(=>4^x=176:11\)

\(=>4^x=16\)

\(=>4^x=4^2\)

\(=>x=2\)

13 tháng 8 2023

`x + 2 3/4 = 5 2/3`

`=> x + 11/4 = 17/3`

`=> x= 17/3 -11/4`

`=>x=35/12`

__

`x - 1 4/5 = 3 2/7`

`=> x- 9/5 = 23/7`

`=> x= 23/7 +9/5`

`=>x=178/35`

__

`x xx 3 1/2 =4 3/4`

`=> x xx 7/2 =19/4`

`=> x= 19/4 : 7/2`

`=> x= 19/4 xx 2/7`

`=> x= 19/14`

__

`x : 2 2/3 = 4 1/3`

`=> x : 8/3 = 13/3`

`=> x= 13/3 xx 8/3`

`=>x=104/9`

a: =>x+11/4=17/3

=>x=17/3-11/4=68/12-33/12=35/12

b: =>x-9/5=23/7

=>x=23/7+9/5=178/35

c: =>x*7/2=4,75

=>x=19/4:7/2=19/14

d: =>x:8/3=13/3

=>x=13/3*8/3=104/9

9 tháng 8 2023

a) \(x-\dfrac{3}{4}=6\times\dfrac{3}{8}\)

\(x-\dfrac{3}{4}=\dfrac{9}{4}\)

=> \(x=\dfrac{9}{4}+\dfrac{3}{4}=3\)

b) \(\dfrac{7}{8}:x=3-\dfrac{1}{2}\)

\(\dfrac{7}{8}:x=\dfrac{5}{2}\)

=> \(x=\dfrac{7}{8}:\dfrac{5}{2}=\dfrac{7}{20}\)

c) \(x+\dfrac{1}{2}\times\dfrac{1}{3}=\dfrac{3}{4}\)

\(x+\dfrac{1}{6}=\dfrac{3}{4}\)

=> \(x=\dfrac{3}{4}-\dfrac{1}{6}=\dfrac{7}{12}\)

d) \(\dfrac{3}{2}\times\dfrac{4}{5}-x=\dfrac{2}{3}\)

\(\dfrac{6}{5}-x=\dfrac{2}{3}\)

=> \(x=\dfrac{6}{5}-\dfrac{2}{3}=\dfrac{8}{15}\)

e) \(x\times3\dfrac{1}{3}=3\dfrac{1}{3}:4\dfrac{1}{4}\)(?)

\(x\times\dfrac{10}{3}=\dfrac{40}{51}\)

=> \(x=\dfrac{40}{51}:\dfrac{10}{3}=\dfrac{4}{17}\)

f) \(5\dfrac{2}{3}:x=3\dfrac{2}{3}-2\)

\(\dfrac{17}{3}:x=\dfrac{5}{3}\)

=> \(x=\dfrac{17}{3}:\dfrac{5}{3}=\dfrac{17}{5}\)

a: =>x-3/4=18/8=9/4

=>x=9/4+3/4=12/4=3

b: =>7/8:x=5/2

=>x=7/8:5/2=7/8*2/5=14/40=7/20

c: x+1/2*1/3=3/4

=>x+1/6=3/4

=>x=3/4-1/6=9/12-2/12=7/12

d: =>12/10-x=2/3

=>6/5-x=2/3

=>x=6/5-2/3=18/15-10/15=8/15

e: =>x*10/3=10/3:17/4=10/3*4/17

=>x=4/17

f: =>17/3:x=13/3-5/2=26/6-15/6=11/6

=>x=17/3:11/6=17/3*6/11=34/11

5 tháng 9 2023

1) \(S=2.2.2..2\left(2023.số.2\right)\)

\(\Rightarrow S=2^{2023}=\left(2^{20}\right)^{101}.2^3=\overline{....6}.8=\overline{.....8}\)

2) \(S=3.13.23...2023\)

Từ \(3;13;23;...2023\) có \(\left[\left(2023-3\right):10+1\right]=203\left(số.hạng\right)\)

\(\) \(\Rightarrow S\) có số tận cùng là \(1.3^3=27\left(3^{203}=\left(3^{20}\right)^{10}.3^3\right)\)

\(\Rightarrow S=\overline{.....7}\)

3) \(S=4.4.4...4\left(2023.số.4\right)\)

\(\Rightarrow S=4^{2023}=\overline{.....4}\)

4) \(S=7.17.27.....2017\)

Từ \(7;17;27;...2017\) có \(\left[\left(2017-7\right):10+1\right]=202\left(số.hạng\right)\)

\(\Rightarrow S\) có tận cùng là \(1.7^2=49\left(7^{202}=7^{4.50}.7^2\right)\)

\(\Rightarrow S=\overline{.....9}\)

15 tháng 12 2022

a: =>3x+27-2x+8=-13*100=-1300

=>x+35=-1300

=>x=-1335

b: =>100x-5050=2750

=>100x=2750+5050=7800

=>x=78

c: =>-2x-8-64:16=198

=>-2x=210

=>x=-105

16 tháng 10 2017

Trả lời giúp mình câu này