(2x - 1)³ = -8

(2x - 1) = (-2)³

=> 2x - 1 = -2

=> 2x = -2 + 1

=> 2x = -1

=> x = -1/2

Vậy x = -1/2

1.2.3.4.5.6.5.4.3.2.1=86400 

k ho mh nha!!!

\(Dk:x\ge5\)

\(\sqrt{4x-20}+\sqrt{x-5}-\frac{1}{3}\sqrt{9x-45}=\sqrt{4\left(x-5\right)}+\sqrt{x-5}-\frac{1}{3}\sqrt{9\left(x-5\right)}=2\sqrt{x-5}+\sqrt{x-5}-\frac{1}{3}.3\sqrt{x-5}=2\sqrt{x-5}=4\Rightarrow\sqrt{x-5}=2\Leftrightarrow x-5=4\Leftrightarrow x=9\left(tmdk\right)\)

\(\left(3x+1\right)\left(3y+2\right)-2=9xy+6x+3y+2-2=9xy+6x+3y⋮3\)

Tổng 2 số là :

​45 + 58 = 113

​Đáp số : 113

​

45 + 78 = 103

\(x^2=2\)

\(\Rightarrow x=\sqrt{2}\)

\(\Rightarrow x\)là số hữu tỉ