Question

Tìm x:

( x - 1 )³ = -8

2^2x-3 - 2. 5² = 5² . 3

Answer 1

1 câu thui nhé

(x-1)³ = -8 = (-2)³

x-1 = -2 => x = -2 +1 = -1

Answer 2

( x - 1 ) ³ = -8

=> ( x - 1 ) ³ = ( - 2 )³

=> x - 1 = 2 => x = 3 .

2^{2x - 3} - 2 . 5² = 5² . 3

=> 5² . 3 + 2 . 5² = 5² . 5

=> 5² . 5 = 2 ^{2x - 3}

=> 125 = 2^{2x - 3}

Answer 3

\(\left(x-1\right)^3=-8\)

\(\Rightarrow\left(x-1\right)^3=-2^3\)

\(\Rightarrow x-1=-2\)

\(\Rightarrow x=-1\)

\(2^{2x-3}-2.5^2=5^2.3\)

\(\Rightarrow2^{2x}:2^3-2.25=25.3\)

\(\Rightarrow2^{2x}:8-50=75\)

\(\Rightarrow2^{2x}:8=125\)

\(\Rightarrow2^{2x}=1000\)

Đến đây thì thấy bí