Lời giải và đáp án:
`a)` `(x-1)^3=125`
`<=>` `(x-1)^3=5^3`
`<=>` `x-1=5`
`<=>` `x=6`
Vậy `x=6`
`b)` `2^(x+2)-2^x=96`
`<=>` `2^x .2^2-2^x=96`
`<=>` `2^x(2^2-1)=96`
`<=>` `2^x .3=96`
`<=>` `2^x=32`
`<=>` `2^x=2^5`
`<=>` `x=5`
Vậy `x=5`
`c)` `(2x+1)^3=343`
`<=>` `(2x+1)^3=7^3`
`<=>` `2x+1=7`
`<=>` `2x=6`
`<=>` `x=3`
Vậy `x=3`
`d)` `720:[41-(2x-5)]=2^3 .5`
`<=>` `41-(2x-5)=720:(2^3 .5)`
`<=>` `41-(2x-5)=18`
`<=>` `2x-5=23`
`<=>` `2x=28`
`<=>` `x=14`
Vậy `x=14`
`e)` `16^x<128^4`
`<=>` `(2^4)^x<(2^7)^4`
`<=>` `2^(4x)<2^28`
`<=>` `4x<28`
`<=>` `x<7`
Vậy `x<7`
