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25 tháng 4 2021

Đáp án: x=1

Lời giải:

5x−23=5x−23= 5−3x25−3x2

⇔2(5x−2)=3(5−3x)2(5x−2)=3(5−3x)

⇔10x−4−15+9x=010x−4−15+9x=0

⇔19x−19=019x−19=0

⇔19(x−1)=019(x−1)=0

⇔x−1=0x−1=0

⇔x=1x=1

Vậy x=1

25 tháng 4 2021

ĐK : x \(\ne\)5

\(\frac{3-x}{5-x}=\left(-\frac{3}{5}\right)^2\)

=> \(\frac{3-x}{5-x}=\frac{9}{25}\)

=> 25(3 - x) = 9(5 - x)

=> 75 - 25x = 45 - 9x

=> 16x = 30

=> x = \(\frac{15}{8}\)(tm)

Vậy x = 15/8 là giá trị cần tìm 

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

14 tháng 8 2023

a) \(2+2+2+2+2=2\times5=10\)

\(2\times5=10\)

\(5+5=2\times5=10\)

\(5\times2=10\)

b) \(3\times5=3+3+3+3+3=15\)

\(5\times3=5+5+5=15\)

\(3\times5=5+5+5=15\)

\(5\times3=3+3+3+3+3=15\)

14 tháng 4 2023

a) 2 + 2 + 2 + 2 + 2 = 10
    2 x 5 = 10
    5 + 5 = 10
    5 x 2 = 10
b) 3 x 5 = 3 + 3 + 3 + 3 + 3 = 15
    5 x 3 = 5 + 5 + 5 = 15
    3 x 5 = 15
    5 x 3 = 15

AH
Akai Haruma
Giáo viên
2 tháng 3 2021

Bạn cần viết đề bài bằng công thức toán để được hỗ trợ tốt hơn. 

4 tháng 3 2021

x^2+2x-3/3+2x/4=x^2/3

3 tháng 7

1; 5.22 + (\(x\) + 3) = 52

   5.4  +  (\(x\) + 3) = 25

    20 + (\(x\) + 3) = 25

             \(x\) + 3 = 25 - 20

             \(x+3\) = 5

             \(x\)       = 5  - 3

            \(x\)        = 2

            Vậy \(x=2\)

3 tháng 7

2; 23 + (\(x\) - 32) = 53 - 43

   8 +  (\(x\) - 9)    = 125 - 64

   8 + (\(x\) - 9) = 61

         \(x\) - 9 = 61 - 8

         \(x\) - 9 = 53

        \(x\)        = 53  + 9

        \(x\)       = 62

        Vậy \(x\) = 62

 

      

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

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

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

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

\(=16\cdot5-8\)

\(=72\)

28 tháng 4 2018

a) \(\left(3x-1\right).\left(\frac{-1}{2}x+5\right)=0\)

\(\Rightarrow3x-1=0\Rightarrow3x=1\Rightarrow x=\frac{1}{3}\)

\(\frac{-1}{2}x+5=0\Rightarrow\frac{-1}{2}x=-5\Rightarrow x=10\)

b) \(3\left(x-\frac{1}{2}\right)-5\left(x+\frac{3}{5}\right)=x+\frac{1}{5}\)

\(3x-\frac{3}{2}-5x-3=x+\frac{1}{5}\)

\(\Rightarrow3x-5x-x=\frac{1}{5}+\frac{3}{2}+3\)

\(-3x=\frac{47}{10}\)

\(x=\frac{-47}{30}\)

c) \(-5.\left(x+\frac{1}{5}\right)-\frac{1}{2}\left(x-\frac{2}{3}\right)=\frac{3}{2}x-\frac{5}{6}\)

\(-5x-1-\frac{1}{2}x+\frac{1}{3}=\frac{3}{2}x-\frac{5}{6}\)

\(-5x-\frac{1}{2}x-\frac{3}{2}x=\frac{-5}{6}+1-\frac{1}{3}\)

\(-7x=\frac{-1}{6}\)

\(x=\frac{1}{42}\)

d) \(3.\left(3x-\frac{1}{2}\right)^3+\frac{1}{9}=0\)

\(3.\left(3x-\frac{1}{2}\right)^3=\frac{-1}{9}\)

\(\left(3x-\frac{1}{2}\right)^3=\frac{-1}{27}\)

\(\left(3x-\frac{1}{2}\right)^3=\left(\frac{-1}{3}\right)^3\)

\(\Rightarrow3x-\frac{1}{2}=\frac{-1}{3}\)

\(3x=\frac{1}{6}\)

\(x=\frac{1}{18}\)

Học tốt nhé bn!
 

11 tháng 8 2021

x = \(\frac{1}{18}\)nha

29 tháng 5 2017

a)    \(\left(3^2-2\right).\left(x-12+35\right)\)\(=\)\(5^2+279:5\)

\(7.\left(x-12+35\right)=80,8\)

\(x-12+35=80,8:7\)

\(x-12+35=\frac{404}{35}\)

\(x-12=\frac{404}{35}-35\)

\(x-12=\frac{-821}{35}\)

\(x=\frac{-821}{35}+12\)

\(x=\frac{-401}{35}\)

b)    \(260:\left(x+4\right)\)\(=\)\(5\left(2^3+5\right)-3\left(3^2+2^2\right)\)

     \(260:\left(x+4\right)=26\)

     \(x+4=260:26\)

    \(x+4=10\)

   \(x=10-4\)

   \(x=6\)

c)   \(7^{x-3}=343\)

    \(7^x:7^3=343\)

    \(7^x=343.7^3\)

    \(7^x=117649\)

vì \(117649=7^6\Rightarrow x=6\)

d)    \(\left(x-3\right)^{2017}=\left(x-3\right)^{2016}\)

\(\Rightarrow\hept{\begin{cases}x-3=1\\x-3=0\end{cases}\Rightarrow\hept{\begin{cases}x=4\\x=3\end{cases}}}\)

e)     \(\left(2^3+3\right).\left(x-5\right)+14\)\(=\)\(5^2+124:2^2\)

      \(\left(2^3+3\right).\left(x-5\right)+14=56\)

       \(\left(2^3+3\right).\left(x-5\right)=56-14\)

       \(\left(2^3+3\right).\left(x-5\right)=42\)

        \(x-5=42:\left(2^3+3\right)\)

        \(x-5=\frac{42}{11}\)

      \(x=\frac{42}{11}+5\)

     \(x=\frac{97}{11}\)

31 tháng 7 2023

1) 2(x + 5) + 3(x + 7) = 41
2x + 10 + 3x + 21 = 41
5x + 31 = 41
5x = 10
x = 2
6) 7(x - 1) + 5(3 - x) = 11x - 10
7x - 7 + 15 - 5x = 11x - 10
2x + 8 = 11x - 10
-9x = -18
x = 2

2) 5(x + 6) + 2(x - 3) = 38
5x + 30 + 2x - 6 = 38
7x + 24 = 38
7x = 14
x = 2

7) 4(2 + x) + 3(x - 2) = 12
8 + 4x + 3x - 6 = 12
7x + 2 = 12
7x = 10
x = 10/7

3) 7(5 + x) + 2(x - 10) = 15
35 + 7x + 2x - 20 = 15
9x + 15 = 15
9x = 0
x = 0

8) 5(2 + x) + 4(3 - x) = 10x - 15
10 + 5x + 12 - 4x = 10x - 15
x + 22 = 10x - 15
9x = 37
x = 37/9

4) 3(x + 4) + (8 - 2x) = 22
3x + 12 + 8 - 2x = 22
x + 20 = 22
x = 2

9) 7(x - 2) + 5(3 - x) = 11x - 6
7x - 14 + 15 - 5x = 11x - 6
2x + 1 = 11x - 6
-9x = -7
x = 7/9

5) 4(x + 5) + 3(7 - x) = 49
4x + 20 + 21 - 3x = 49
x + 41 = 49
x = 8

10) 5(3 - x) + 5(x + 4) = 6 + 4x
15 - 5x + 5x + 20 = 6 + 4x
35 = 6 + 4x
4x = 29
x = 29/4

15 tháng 2 2020
https://i.imgur.com/zKeoHqB.jpg
28 tháng 8 2021

a,

\(5^{x+4}-3.5^{x+3}=2.5^{11}\)

\(\Rightarrow5^{x+3}\left(5-3\right)=2.5^{11}\)

\(\Rightarrow5^{x+3}2=2.5^{11}\)

\(\Rightarrow5^{x+3}=5^{11}\)

\(\Rightarrow x+3=11\)

\(\Rightarrow x=8\)

28 tháng 8 2021

b, (Check lai xem de sai o dau khong nhe)

\(3.5^{x+2}+4.5^{x+3}=19.5^{10}\)

Dat 5x ra ben ngoai

\(\Rightarrow5^x.5^23+5^x:5^{-3}.4\)

\(\Rightarrow5^x\left(5^2.3+5^{-3}.4\right)\)

\(\Rightarrow5^x\left(5^{-3}.5^5.3+5^{-3}.4\right)\)

\(\Rightarrow5^x[5^{-3}\left(5^53+4\right)\)

\(\Rightarrow5^x[5^{-3}\left(3125.3+4\right)\)

\(\Rightarrow5^x\left(5^{-3}\right).9379\)

=> Khong tim duoc gia tri cua x \(\Rightarrow x\in\varnothing\)