Toán Lớp 6: (1/2)^x=1/8 5^2x-1=125 5^2x+1=125^x+25 2x=4^5.4^3 2^4-x/16^5=32^6

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1. (1/2)^x = 1/8

   -> (1/2)^x = (1/2)^3

   -> x =3

   Vậy x =3

   $\\$

   5^{2x-1} = 125

   -> 5^{2x-1} = 5^3

   -> 2x -1 =3

   -> 2x =4

   -> x =2

   Vậy x =2

   $\\$

   5^{2x+1} = 125^{x + 25}

   5^{2x+1}  = 5^{3x+75}

   -> 2x +1 = 3x +75

   -> 3x -2x = 1 – 75

   -> x = -74

   Vậy x = -74

   $\\$

   2x = 4^5 . 4^3

   -> 2x = 4^8 

   -> x = 2^16 : 2 = 2^15

   Vậy x =2^15

   $\\$

   {2^4-x}/{16^5} =32^6

   -> 2^4 -x = 32^6 . 16^5

   -> 16 -x = 2^30 . 2^20

   -> 16 – x = 2^50

   -> x = 16 -2^50

   Vậy x =16 -2^50

   Trả lời
2. Giải đáp:

   (1/2)^x=1/8

   =>(1/2)^x=(1/2)^3

   =>x=3

   Vậy x=3

   5^{2x-1}=125

   =>5^{2x-1}=5^3

   =>2x-1=3

   =>2x=4

   =>x=2

   Vậy x=2

   5^{2x+1}=125^{x+25}

   =>5^{2x+1}=(5^3)^{x+25}

   =>5^{2x+1}=5^{3(x+25)}

   =>2x+1=3(x+25)

   =>2x+1=3x+75

   =>3x-2x=1-75

   =>x=-74

   Vậy x=-74

   2x=4^5*4^3

   =>2x=4^{5+3}

   =>2x=4^8

   =>x=(4^8)/2=(2^16)/2=2^15

   Vậy x=2^15

   (2^4-x)/16^5=32^6

   =>(2^4-x)/(2^4)^5=(2^5)^6

   =>(2^4-x)/2^20=2^30

   =>2^4-x=2^50

   =>x=2^4-2^50

   Vậy x=2^4-2^50

   Trả lời