Question

tìm x:4.(2.x-1)^3- 17=10^2-3^2

Answer 1

\(4\left(2x-1\right)^3-17=10^2-3^2\)

\(\Rightarrow4\left(2x-1\right)^3-17=100-9\)

\(\Rightarrow4\left(2x-1\right)^3-17=91\)

\(\Rightarrow4\left(2x-1\right)^3=91+17\)

\(\Rightarrow4\left(2x-1\right)^3=108\)

\(\Rightarrow\left(2x-1\right)^3=108:4\)

\(\Rightarrow\left(2x-1\right)^3=27\)

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

\(\Rightarrow2x-1=3\)

\(\Rightarrow2x=3+1\)

\(\Rightarrow2x=4\)

\(\Rightarrow x=4:2\)

\(\Rightarrow x=2\)

Answer 2

=>4(2x-1)^3=100-9+17=108

=>(2x-1)^3=27

=>2x-1=3

=>2x=4

=>x=2