Question

\((x-1)^3=125\)

\(2^{x+2}-2^x=96\)

\(\left(2x+1\right)^3=343\)

\(720:\left[41-\left(2x-5\right)\right]=2^3.5\)\(16^x< 128^4\)

 

Answer 1

[X-1]^3=125

[x-1]^3=5^3

x-1=5

x=5+1

x=6

Vậy x=6

Answer 2

a) \(\left(x-1\right)^3=125\)

\(\Rightarrow x-1=5\)

\(\Rightarrow x=6\)

b) \(2^{x+2}-2^x=96\)

\(\Rightarrow2^x.2^2-2^x=96\)

\(\Rightarrow2^x.3=96\)

\(\Rightarrow2^x=32=2^5\)

\(\Rightarrow x=5\)

c) \(\left(2x+1\right)^3=343=7^3\)

\(\Rightarrow2x+1=7\)

\(\Rightarrow x=3\)

Answer 3

\(\left(x-1\right)^3=125\)\(\Rightarrow\left(x-1\right)^3=5^3\Rightarrow x-1=5\)

\(\Rightarrow x=5+1=6\)

\(\left(2x+1\right)^3=343\Rightarrow\left(2x+1\right)^3=7^3\Rightarrow2x+1=7\)

\(2x=7-1=6\Rightarrow x=6:2=3\)