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222-9+11+12:2*14+14 = ? ( )

## 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

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

1. 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

2. (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