Question

tìm x: 4-x=2(x-4)²

Answer 1

`4-x = 2(x-4)^2`

`<=> 4-x = 2(x^2 -8x+16)`

`<=> 4-x = 2x^2 - 16x + 32`

`<=> 4-x -2x^2 +16x -32 =0`

`<=> -2x^2+15x -28 =0`

`<=> 2x^2 -15x +28 =0`

`<=> 2x^2 - 7x -8x +28 =0`

`<=> (x-4)(2x-7)=0`

`<=> [(x=4),(x=7/2):}`

Answer 2

4-x=2(x^2-2.4x+4^2)

4-x=2(x^2-8x+16)

4-x=2x^2-16x+32

4-x-2x^2+16x-32=0

-2x^2+15x-28=0