đề bài chắc là tìm x

Hổng hiểu, đề bài đâu

nhìn cũng hổng hiểu à

tìm x đó

a) = (x+3).(x-3)^2-(x-3)(x+3)^2

=(x^2-9)(x-3)-(x^2-9)(x+3)

=(x^2-9)(x-3-x-3)

=-6(x^2-9)

các câu còn lại tương tự

\(a,\left(x+3\right)\left(x^2-3x+9\right)-\left(x-3\right)\left(x^2+3x+9\right)\)

\(=x^3+3-\left(x^3-3\right)\)

\(=x^3+3-x^3+3\)

\(=6\)

\(b,\left(x-5\right)\left(x^2+5x+25\right)-\left(x+5\right)\left(x^2-5x+25\right)\)

\(=x^3-5^3-x^3-5^3\)

\(=-125-125\)

\(=-250\)

\(25+\frac{x}{49}+x=\frac{3}{5}\)

\(\frac{x}{49}+x=\frac{3}{5}-25\)

\(x\left(\frac{1}{49}+1\right)=-24.4\)

\(x\cdot\frac{50}{49}=\frac{61}{25}\)

\(x=\frac{61}{25}:\frac{50}{49}\)

\(x=\frac{2989}{1250}\)

Ai biết chỉ mình nha 

1. 11(x-9)=77

x-9=7

x=16

2. 4(x-3)=48

x-3=12

x=15

3.3(x-8)=81

(x-8)=27

x=35

\(40-21:\left(2.x+3\right)=33\)

\(21:\left(2.x+3\right)=40-33\)

\(21:\left(2.x+3\right)=7\)

\(\left(2.x+3\right)=21:7\)

\(\left(2.x+3\right)=3\)

\(2.x=3-3\)

\(2.x=0\)

\(x=0:2\)

\(x=0\)

1) \(...\Rightarrow x-7=0\Rightarrow x=7\)

2) \(...\Rightarrow x-4=0\Rightarrow x=4\)

3) \(...\Rightarrow6x-12=0\Rightarrow6x=12\Rightarrow x=12:6=2\)

4) \(...\Rightarrow9x-27=0\Rightarrow9x=27\Rightarrow x=27:9=3\)

5) \(...\Rightarrow15-x=30-25\Rightarrow15-x=5\Rightarrow x=15-5=10\)

6) \(...\Rightarrow43-24+x=20\Rightarrow19+x=20\Rightarrow x=20-19=1\)

7) \(...\Rightarrow2x+14-17=25\Rightarrow2x-3=25\Rightarrow2x=28\Rightarrow x=28:2=14\)

8) \(...\Rightarrow3x+21-15=27\Rightarrow3x-6=27\Rightarrow3x=33\Rightarrow x=33:3=11\)

9) \(...\Rightarrow15+4x-8=95\Rightarrow4x+7=95\Rightarrow4x=88\Rightarrow x=88:4=22\)

10) \(...\Rightarrow20-x-14=5\Rightarrow6-x=5\Rightarrow x=6-5=1\)

11) \(...\Rightarrow24+15-3x=27\Rightarrow39-3x=27\Rightarrow3x=39-27\Rightarrow3x=12\Rightarrow x=12:3=4\)

2346 : (25 + x) = 23

=> 25 + x = 2346 : 23 = 102

=> x = 102 - 25  =  77

Vậy x = 77

2(x-3) + 5(x+4) = 49

=> 2x - 6 + 5x + 20 = 49

=> 7x + (20 - 6) = 49

=> 7x + 14 = 49

=> 7x = 49 - 14 = 35

=> x = 35 : 7 = 5

Vậy x = 5

(2x-10)³ . 25¹⁰⁰⁷ = \(5^2.5^{2015}\)

\(\left(2x-10\right)^3.5^{2014}=5^{2014}.5^3\)

\(\left(2x-10\right)^3=5^3\)

2x - 10 = 5

=> 2x = 5 + 10 = 15

=> x = 15  2 = 7,5

Vậy x = 7,5

1. a. 2346:(25+x)=23

=> 25+x=2346:23

=> 25+x=102

=> x=102-25

=> x=77

b. 2(x-3)+5(x+4)=49

=> 2x-6+5x+20=49

=> 7x+14=49

=> 7x=49-14

=> 7x=35

=> x=35:7

=> x=5

c. (2x-10)³.25¹⁰⁰⁷=5².5²⁰¹⁵

=> (2x-10)³.(5²)¹⁰⁰⁷=5²⁰¹⁷

=> (2x-10)³.5²⁰¹⁴=5²⁰¹⁷

=> (2x-10)³=5²⁰¹⁷:5²⁰¹⁴

=> (2x-10)³=5³

=> 2x-10=5

=> 2x=5+10

=> 2x=15

=> x=15:2

=> x=7,5

=997866

5 + ( x + 27 ) = 64

a) \(\Rightarrow x+27=59\Rightarrow x=32\)

b) \(\Rightarrow x-2=39\Rightarrow x=41\)

c) \(\Rightarrow x+5=-322\Rightarrow x=-327\)

d) \(\Rightarrow5x=35\Rightarrow x=7\)

e) \(\Rightarrow4\left(x-5\right)=56\Rightarrow x-5=14\Rightarrow x=19\)

f) \(\Rightarrow15+x=37\Rightarrow x=22\)

g) \(\Rightarrow7\left(13-x\right)=35\Rightarrow13-x=5\Rightarrow x=8\)

h) \(\Rightarrow10\left(x+1\right)=100\Rightarrow x+1=10\Rightarrow x=9\)

d)5( x+4)=135-35

       x+4=100:5

       x    =20-4

      x     =16

d) 135 - 5 (x+4) = 35

5 (x+4) = 135 - 35

5 (x+4) = 100

(x+4) = 100 : 5

x + 4 = 20

x = 20 - 4

x = 16

e) 25 + 3 ( x - 8 ) = 106 

3  ( x - 8 ) = 106 - 25 

3  ( x - 8 ) = 81 

x - 8 = 81 : 3 

x - 8 = 27 

x = 27 + 8 

x = 35 

f) 2x – 49 = 5. 32

2x - 49 = 160

2x = 160 + 49

2x = 209

x = 209 : 2

x = 104,5

d)\(135-5\left(x+4\right)=35\)

⇔\(5\left(x+4\right)=100\)

⇔\(x+4=20\)

⇔\(x=16\)

e)\(25+3\left(x-8\right)=106\)

⇔\(3\left(x-8\right)=81\)

⇔\(x-8=27\)

⇔\(x=35\)

f)\(2x-49=5.32\)

⇔\(2x-49=160\)

⇔\(2x=209\)

⇔\(x=\dfrac{209}{2}\)

12 mình chịu

11/15 + 8/5=                   Tính phân số

6/7 - 5/21=

25/4 x 16/100

7 x 2/49 =

4/3 : 2/9

5/8 : 25 =

đây là kết quả của mình nhé .