giúp tôi nhá

a) 5(x+7) - 10 = 2^3 . 5

 5(x+7 ) -10 = 8 . 5 = 40

5(x+7) = 40 + 10 = 50

x + 7 = 50 : 5 = 10

x = 10 - 7 = 3

a) 72.5–(2x+1)=630:972.5–(2x+1)=630:9

⇒245–2x–1=70⇒245–2x–1=70

⇒−2x=−22+70⇒−2x=−22+70

⇒−2x=−174⇒−2x=−174

⇒x=87⇒x=87

b)(10−4x)+120:23=17

10−4x+15=17

10−4x=17−15

10−4x=2

4x=10−2

4x=8

x=8:4

x=2

 

a: \(3^2\cdot\frac{1}{243}\cdot81^2\cdot\frac{1}{3^2}\)

\(=\frac{3^2}{3^5}\cdot\frac{3^8}{3^2}=\frac{1}{3^3}\cdot3^6=3^3=27\)

b: \(4^6\cdot256^2\cdot2^4=\left(2^2\right)^6\cdot\left(2^8\right)^2\cdot2^4\)

\(=2^{12}\cdot2^{16}\cdot2^4=2^{12}\cdot2^{20}=2^{32}\)

c: \(4^6\cdot9^5+6^9\cdot120\)

\(=2^{12}\cdot3^{10}+2^9\cdot3^9\cdot2^3\cdot3\cdot5\)

\(=2^{12}\cdot3^{10}+2^{12}\cdot3^{10}\cdot5\)

\(=2^{12}\cdot3^{10}\cdot6=2^{13}\cdot3^{11}\)

Ta có \(8^4\cdot3^{12}-6^{11}\)

\(=2^{12}\cdot3^{12}-2^{11}\cdot3^{11}\)

\(=2^{11}\cdot3^{11}\left(2\cdot3-1\right)=2^{11}\cdot3^{11}\cdot5\)

Ta có: \(A=\frac{4^6\cdot9^5+6^9\cdot120}{8^4\cdot3^{12}-6^{11}}\)

\(=\frac{2^{13}\cdot3^{11}}{2^{11}\cdot3^{11}\cdot5}=\frac{2^2}{5}=\frac45\)

d: \(4^2\cdot25^2+32\cdot125\)

\(=2^4\cdot5^4+2^5\cdot5^3\)

\(=2^4\cdot5^3\left(5+2\right)=2^4\cdot5^3\cdot7\)

\(B=\frac{4^2\cdot25^2+32\cdot125}{2^3\cdot5^2}\)

\(=\frac{2^4\cdot5^3\cdot7}{2^3\cdot5^2}=2\cdot5\cdot7=70\)

1)

a) 2x + 5 = 3⁴ : 3²

2x + 5 = 3²

2x + 5 = 9

2x = 9 - 5

2x = 4

x = 4 : 2

x = 2

b) (3x - 24).73 = 2.74

(3x - 24).73 = 148

3x - 24 = 148/73

3x = 148/73 + 24

3x = 1900/73

x = 1900/73 : 3

x = 1900/219

c) [3.(42 - x)] + 15 = 23.3

126 - 3x + 15 = 69

141 - 3x = 69

3x = 141 - 69

3x = 72

x = 72 : 3

x = 24

d) 126 + (132 - x) = 300

132 - x = 300 - 126

132 - x = 174

x = 132 - 174

x = -42

2)

a) 120 - (x + 55) = 60

x + 55 = 120 - 60

x + 155 = 60

x = 60 - 55

x = 5

b) (7x - 11).3 = 25.52 + 200

(7x - 11).3 = 1500

7x - 11 = 1500 : 3

7x - 11 = 500

7x = 500 + 11

7x = 511

x = 511 : 7

x = 73

c) 2x + 2x + 4 = 544

4x = 544 - 4

4x = 540

x = 540 : 4

x = 135

92084

học tốt

1+23*45*89-42+10=92084

8: =>2x=210

hay x=105

6567578.X.6567578.Y:6098+6099+......+10000=200000000

1) 25 + 91 + 75 + 101

= (25+75) + (91 + 101)

= 100 + 192

= 292

2) 41 x 39 - 41 x 9

= 41 x (39 - 9)

= 41 x 30

= 1230

3) 710 x 99 + 710

= 710 x 99 + 710 x 1

= 710 x (99 + 1)

= 710 x 100

= 71000

4) 17 x 85 + 15 x 17 - 120

= 17 x (85 + 15) - 120

= 17 x 100 -120

= 1700 -120

= 1580

5) (39 x 42 - 37 x 42) : 42

= 42 x (39 - 37) : 42

= 42 x 2 : 42

= 84 : 42

=2

6) 120 - 48 - 52

= 120 - (48 + 52)

= 120 - 100

= 20

7) 23 x 75 + 25 x 23 + 180

= 23 x (75 + 25) +180

= 23 x (75 + 25) +180

= 23 x 100 + 180

= 2300 +180

=2480

8) 2448 : [119 - (23 - 6)]

= 2448 : (119 - 17)

= 2448 : 102

= 24 

(x-42) - 17 = 127

=> x - 42 = 127 + 17 = 144

=> x = 144 + 42 = 186

23(x+1) = 69

=> x + 1 = 69 : 23 = 3

x = 3 - 1 = 2

2x + 5 = 120 : 2 = 60

=> 2x = 60 - 5 = 55

x = 55 : 2 = 27,5

5x - 2 = 613

=> 5x = 613 + 2 = 615

x = 615 : 5 = 123

a)(x-42)-17=127

(x-42)=127+17

(x-42)=144

x=144+42

x=186

b)23(x+1)=69

(x+1)=69:23

(x+1)=3

x=3-1

x=2

c)2.x+5=120:2

2.x+5=60

2.x=60-5

2.x=55

x=55:2

x=27,5

d)5.x-2=613

5.x=613+2

5.x=615

x=615:5

x=123

1) Tính

a) 10-(-7)+36-(-106)

= 10 + 7 + 36 + 106

= 17 + 36 + 106

= 53 + 106

= 159

b) 129 - 5. {29-(6-1)² }

= 129 - 5. { 29 - 5² }

= 129 - 5. { 29 - 25 } 

= 129 - 5. 4

= 129 - 20

= 109

c)  42-(-50) + (-42) - 120

= 42+ (-42) -  ( 120 - 50 )

= 0 - 70

= - 70

a, 10 -(-7)+36-(-106)=10 +7+36+106=17+142=159