\(\Leftrightarrow\)\(x-\left(\frac{13x}{18}-\frac{4}{18}\right)=\frac{4}{9}\)

\(\Leftrightarrow\)\(\frac{18x}{18}-\frac{13x}{18}+\frac{4}{18}=\frac{4}{9}\)

\(\Leftrightarrow\)\(\frac{5x}{18}=\frac{4}{9}-\frac{4}{18}\)

\(\Leftrightarrow\)\(\frac{5x}{18}=\frac{2}{9}\)

\(\Leftrightarrow\)\(5x=\frac{18.2}{9}\)

\(\Leftrightarrow\)\(5x=4\)

\(\Leftrightarrow\)\(x=\frac{4}{5}\)

5: (x-1)(x-5)=(x-1)(x-2)

=>(x-1)(x-5)-(x-1)(x-2)=0

=>(x-1)(x-5-x+2)=0

=>-3(x-1)=0

=>x-1=0

=>x=1

6: \(6\left(x-3\right)\left(x-4\right)-6x\left(x-2\right)=4\)

=>\(6\left(x^2-7x+12\right)-6x^2+12x=4\)

=>\(6x^2-42x+72-6x^2+12x=4\)

=>-30x=4-72=-68

=>\(x=\frac{68}{30}=\frac{34}{15}\)

7: -(x+3)(x-4)+(x+1)(x-1)=10

=>\(-\left(x^2-x-12\right)+x^2-1=10\)

=>\(-x^2+x+12+x^2-1=10\)

=>x+11=10

=>x=-1

8: (2x-1)(x-2)-(2x-7)(x+3)=3

=>\(2x^2-4x-x+2-\left(2x^2+6x-7x-21\right)=3\)

=>\(2x^2-5x+2-\left(2x^2-x-21\right)=3\)

=>\(2x^2-5x+2-2x^2+x+21=3\)

=>-4x+23=3

=>-4x=-20

=>x=5

9: \(\left(x-5\right)\left(4-x\right)-\left(x-1\right)\left(x+3\right)=-2x^2\)

=>\(-\left(x^2-9x+20\right)-\left(x^2+2x-3\right)=-2x^2\)

=>\(-x^2+9x-20-x^2-2x+3=-2x^2\)

=>7x-17=0

=>7x=17

=>x=17/7

10: (4x+1)(x-3)-(x-7)(4x-1)=15

=>\(4x^2-12x+x-3-\left(4x^2-x-28x+7\right)=15\)

=>\(4x^2-11x-3-4x^2+29x-7=15\)

=>18x-10=15

=>18x=25

=>x=25/18

11: \(\left(x+1\right)\left(x^2-x+1\right)-x\left(x^2-3\right)=4\)

=>\(x^3+1-x^3+3x=4\)

=>3x=4-1=3

=>x=1

12: \(\left(x-3\right)\left(x^2+3x+9\right)+x\left(5-x^2\right)=6x\)

=>\(x^3-27+5x-x^3=6x\)

=>6x=5x-27

=>x=-27

13: (3x-5)(x+1)-(3x-1)(x+1)=x-4

=>(x+1)(3x-5-3x+1)=x-4

=>-4(x+1)=x-4

=>-4x-4=x-4

=>-4x-x=0

=>-5x=0

=>x=0

14; 5(x-3)(x-7)-(5x+1)(x-2)=8

=>\(5\left(x^2-10x+21\right)-\left(5x^2-10x+x-2\right)=8\)

=>\(5x^2-50x+105-5x^2+9x+2=8\)

=>-41x=8-2-105=6-105=-99

=>x=99/41

nhiều quá :((

\(a,2\left(x-5\right)-3\left(x+7\right)=14\)

\(2x-10-3x-21=14\)

\(-x-31=14\)

\(-x=45\)

\(x=45\)

\(b,5\left(x-6\right)-2\left(x+3\right)=12\)

\(5x-30-2x-6=12\)

\(3x-36==12\)

\(3x=48\)

\(x=16\)

\(c,3\left(x-4\right)-\left(8-x\right)=12\)

\(3x-12-8+x=0\)

\(4x-20=0\)

\(4x=20\)

\(x=5\)

Cố nốt nha bn ! 

cảm ơn, bn nha:)))

mà hình như bạn TOP 3 trả lời câu hỏi pải ko nhỉ???

dễ thấy

2014 x 3 - 2014 x 2 - 2014

=2014  x (3-2-1) = 2014 x 0 =0

do đó (1+2+3+.....+109) x (2014 x 3 - 2014 x 2 - 2014)=(1+2+3+...+109) x 0 = 0

=5995 x 2014 x (3-2-1)

=5995 x 2014 x 0

=0

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

1) 2(x + 5) + 3(x + 7) = 41

2x + 10 + 3x + 21 = 41

5x + 31 = 41

5x = 41 - 31

5x = 10

x = 10 : 5

x = 2

2) 5(x + 6) + 2(x - 3) = 38

5x + 30 + 2x - 6 = 38

7x + 24 = 38

7x = 38 - 24

7x = 14

x = 14 : 7

x = 2

3) 7(5 + x) + 2(x - 10) = 15

35 + 7x + 2x - 20 = 15

9x + 15 = 15

9x = 15 - 15

9x = 0

x = 0

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

3x + 12 + 8 - 2x = 22

x + 20 = 22

x = 22 - 20

x = 2

5) 4(x + 5) + 3(7 - x) = 49

4x + 20 + 21 - 3x = 49

x + 41 = 49

x = 49 - 41

x = 8

6) 7(x - 1) + 5(3 - x) = 11x - 10

7x - 7 + 15 - 5x = 11x - 10

2x - 11x + 8 = -10

-9x = -10 - 8

-9x = -18

x = -18 : (-9)

x = 2

7) 4(2 + x) + 3(x - 2) = 12

8 + 4x + 3x - 6 = 12

7x + 2 = 12

7x = 12 - 2

7x = 10

x = 10/7

8) 5(2 + x) + 4(3 - x) = 10x - 15

10 + 5x + 12 - 4x = 10x - 15

10x - 15 = x + 22

10x - x = 22 + 15

9x = 37

x = 37/9

9) 7(x - 2) + 5(3 - x) = 11x - 6

7x - 14 + 15 - 5x = 11x - 6

11x - 6 = 2x + 1

11x - 2x = 1 + 6

9x = 7

x = 7/9

10) 5(3 - x) + 5(x + 4) = 6 + 4x

15 - 5x + 5x + 20 = 6 + 4x

6 + 4x = 35

4x = 35 - 6

4x = 29

x = 29/4

=(1+2+3+4+5+6+7+.....+108+109)x(2014x(3-2-1))

=(1+2+3+4+5+6+7+.....+108+109)x(2014x0)

=Ax0

=0

   ( 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 ) x ( 2014 x 3  - 2014 x 2 - 2014 )

= ( 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 ) x              0

=                      0

0 nhân với số nào cũng bằng 0

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