`( 5 - 1/2x)^2 = ( 8^2 . 16)/4`
`( 5 - 1/2x)^2 = ( ( 2^3)^2 . 2^4)/(2^2)`
`( 5 - 1/2x)^2 = ( 2^6 . 2^4)/(2^2)`
`(5 - 1/2x)^2 = (2^10)/(2^2)`
`(5 - 1/2x)^2 = 2^8`
`( 5 - 1/2x)^2 = (2^4)^2`
`(5 - 1/2x)^2 = 16^2`
`5 - 1/2x = 16`
`1/2x = 5 - 16`
`1/2x = -11`
`x = -11 : 1/2`
`x = -22`
Vậy `x = -22`
`#caty09`