\(\Leftrightarrow23\left(14-4\right)-4\left(x+5\right)=25\)

\(\Leftrightarrow230-25=4\left(x+5\right)\)

\(\Leftrightarrow205=4x+20\)\(\Leftrightarrow4x=185\)\(\Leftrightarrow x=\dfrac{185}{4}\)

\(14.23+4.23-4.\left(x+5\right)=30\)

<=>\(23\left(14+4\right)-4\left(x+5\right)=30\)

<=> \(23.18-4\left(x+5\right)=30\)

<=> \(414-4\left(x+5\right)=30\)

<=> \(-4\left(x+5\right)=-384\)

<=> \(x+5=96\)

<=> \(x=91\)

Vậy x= 91

a)x+2=-5

x=-5-2

x=-7

b)2x-30=14

2x=14+30

2x=44

x=44/2

x=22

c)14*23-4*23-4*(x+5)=30

(14-4)*23-4*(x+5)=30

10*23-4*(x+5)=30

230-4*(x+5)=30

4*(x+5)=230-30

4*(x+5)=200

x+5=200/4

x+5=50

x=50-5

x=45

d)3^x/3^5=45/5

3^x-5=9

3^x-5=3^2

x-5=2

x=2+5

x=7

2)x=2+2+0+1+0+2+0+1+1=9;y=9;z=9

a)x+2=-5

x=-5-2

x=-7

b)2x-30=-14

2x=-14+30

2x=16

x=16:2

x=8

c)14.23-4.23-4(x+5)=30

23(14-4)-4(x+5)=30

23.10-4(x+5)=30

230-4(x+5)=30

4(x+5)=230-30

4(x+5)=200

x+5=200:4

x+5=50

x=50-5

x=45

d)3^x:3⁵=45:5

3^x:3⁵=9

3^x:3⁵=3²

x:5=2

x=2.5

x=10

2)z=3

câu a: x=-7

câu b:x=8

câu c:không có giá trị

câu d:x=7

a ) x=3

b)2x=-14+30

=>2x=16

=>x=8

c)=(14-4).23-4(x+5)=30

=>230-4(x+5)=30

=>4(x+5)==30+230=260

=>x+5=260/4=65

=>x=65-5=60

d)=\(3^x\):\(3^5\)=9

=>3^x=9.3^5=2187

=>x=7

a, x = 28

b, x = 1

c, x = 24

d, x = 3

a,

=85.35-85.27-35.85+35.27

=85.35+85.(-27)-35.85+35.27

=85[35+(-27)+(-35)]+35.27

=85.(-27)+35.27

=-85.27+35.27

=27.[(-85)+35]

=27.(-50)

=-1350

các câu còn lại cũng vậy

a, 85 x ( 35- 27 ) - 35 x ( 35 - 27 )

85 x 8 - 35 x 8

8 x ( 85 - 35 ) 

8 x 50 = 400

b, ( -45 ) x 69 + 30 x ( -45 ) +( -45)

( -45 ) x ( 69 + 30 + 1)

-45 x 100 = -4500

c , 26 + 7 x ( 4 - 12 )

26 + 7 x ( - 8 )

26 + ( -56 )=(- 30)

d , 127 - 18 x ( 5 + 6 )

127 - 18 x 11

127 - 180 + 18

-53 + 18 = - 35

a,  2 3 x + 5 2 x = 2 5 2 + 2 3 - 33

8x+25x = 33

33x = 33

x = 1

b,  260 : x + 4 = 5 2 3 + 5 - 3 3 2 + 2 2

260:(x+4) = 5.13–3.13

x+4 = 260:26

x+4 = 10

x = 6

c,  720 : [ 41 - 2 x - 5 ] = 2 3 . 5

41–(2x–5) = 720:40

2x–5 = 41–18

2x = 28

x = 14

d,  3 2 - 2 x - 12 + 35 = 5 2 + 279 : 3 2

7(x–12)+35 = 56

7(x–12) = 21

x–12 = 3

x = 15

a) 70 - 5.(2x-3)=45

5.(2x-3)=70-45

10x-15 =25

10x     =25 +15

10x     =40

x        =40:10

x        = 4

b)6.(5x+35) =330

5x +35 = 330 : 6

5x +35 =55

5x = 55-35

5x = 20

x = 20 : 5

x = 4

c)936-(4.x+24)=72

4x+24 =936 - 72

4x+24 =864

4x = 864 - 24

4x = 840

x = 840 :4

x = 210

d)(x+1)+(x+3)+(x+5)

x+1+x+3+x+5=30

(x+x+x)+(1+3+5) = 30

3x + 9 =30

3x = 30-9

3x =21

x = 21 : 3

x = 7

e)Vì số lượng x bằng  số số hạng nên số lượng x là :

(100 - 2) : 2 + 1 = 50 (số x)

Tổng 2 +4+6+8+...+100 là :

(100+2) x 50 : 2 = 2550

Ta có :

50 x + 2550 = 2650

50x = 2650 -2550

50x = 100

x = 100 : 50

x = 2

Tick nghen !