a). 5^x = 125

=>5^x = 5³

=> x = 3

b) 3^2x = 81

=> 3^2x = 3⁴

=> 2x = 4

=> x = 2

c). 5^2x-3 – 2.5² = 5² .3

=>5^2x: 5³ = 5² .3 + 2.5²

=>5^2x: 5³ = 5² .5

=>
5^2x = 5² .5.5³

=>5^2x = 5⁶

=> 2x = 6

=> x=3

a) 5x = 125

x = 125 : 5

x = 25

b) 32x = 81

x = 81 : 32

x = 81/ 32

c) 52x - 3 - 2.52 = 52.3

52x - 3 - 104 = 156

x - 3 - 104 = 156 : 52

x - 3 - 104 = 3

x - 3 = 3 + 104

x - 3 = 107

x = 107 + 3

x = 110

Ko chắc lắm , sai thì Sorry nhé .

\(a,\\ 5x=125\\ < =>x=125:5\\ < =>x=25\)

\(b,\\ 32x=81\\ < =>x=81:32\\ < =>x=\frac{81}{32}\)

\(c,\\ 52x-3-2.52=52.3\\ < =>52x-3-104=156\\ < =>52x-107=156\\ < =>52x=156+107\\ < =>52x=263\\ < =>x=x=\frac{263}{52}\)

b) 3^2x = 81

    3^2x = 3⁴

=> 2x = 4

=>   x = 2

a). 5^2x-3 – 2.5² = 5² .3 

             5^2x: 5³ = 5² .3 + 2.5² 

             5^2x: 5³ = 5² .5

                   5^2x = 5² .5.5³ 

                   5^2x = 5⁶

               => 2x = 6

                  => x=3

a, x = 28

b, x = 1

c, x = 24

d, x = 3

\(\Leftrightarrow5^{2x-3}-2.25=25.3\\ \Leftrightarrow5^{2x-3}-50=75\\ \Leftrightarrow5^{2x-3}=125\\ \Leftrightarrow2x-3=3\\ \Leftrightarrow x=3\)

a, 2.(x – 5)+7 = 77

<=> 2.(x – 5) = 70 <=> x – 5 = 35 <=> x = 40

b,  x - 1 3 - 3 5 : 3 4 + 2 . 2 3 = 14

<=> x - 1 3 - 3 + 2 4 = 14

<=>  x - 1 3 = 14 + 3 - 16 = 1

<=> x – 1 = 1 <=> x = 2

c,  1 + 2 + 2 2 + 2 3 + . . . + 2 2016 = 2 x - 1 - 1

Đặt: A = 1 + 2 + 2 2 + 2 3 + . . . + 2 2016 => 2A =  2 + 2 2 + 2 3 + . . . + 2 2017

=> 2A – A = ( 2 + 2 2 + 2 3 + . . . + 2 2017 ) – ( 1 + 2 + 2 2 + 2 3 + . . . + 2 2016 )

=> A =  2 2017 - 1

Ta có:  1 + 2 + 2 2 + 2 3 + . . . + 2 2016 = 2 x - 1 - 1 =>  2 2017 - 1 =  2 x - 1 - 1 => x = 2018

d,  5 2 x - 3 - 2 . 5 2 = 5 2 . 3

<=>  5 2 x - 3 = 5 2 . 3 + 5 2 . 2

<=>  5 2 x - 3 = 5 2 . ( 3 + 2 )

<=>  5 2 x - 3 = 5 3

<=> 2x – 3 = 3 => x = 3

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51

a x=7 hoặc -7

b ko có x

c x=-6 hoặc 6

d x=7 hoặc -3

e x=1 hoac 7

f x=4 hoac 10

52

a -5<x<5

b -7<x>7

c x = R

d x < (-1)

53

x+y=10 hoac -10

Mọi người ơi giúp mik cái đi mà ~w.

a) 52x - 3 - 2 . 52 = 52 . 3

x - 3/52 - 2 = 3

x = 3 + 2 + 3/52

x = 263/52

b) 740 / (x + 10) = 102 - 2 . 13

740 / (x + 10) = 76

x + 10 = 740 / 76

x + 10 = 185/19

x = 185/19 - 10

x = -5/19

c) 65 - 4x + 2 = 20140

65 - 4x = 20140 - 2

65 - 4x = 20138

4x = 65 - 20138

4x = -20073

x = -20073/4

d) 120 + 2 . (3x - 17) = 214

60 + 3 . x - 17 = 107

20 + x - 17/3 = 107/3

20 + x = 107/3 + 17/3

20 + x = 124/3

x = 124/3 - 20

x = 64/3

e) 41 - 2x + 1 = 9

42 - 2x = 9

21 - x = 9/2

x = 21 - 9/2

x = 33/2