Question

Tìm x biết: 25x^2-4-3(5x-2)^2=0

Answer 1

=>(5x-2)(5x+2-15x+6)=0

=>(5x-2)(-10x+8)=0

=>x=2/5 hoặc x=4/5

Answer 2

`25x^2 - 4 - 3(5x-2)^2=0`

`=>(5x-2)(5x+2-15x+6)=0`

`=> (5x-2)(-10x+8)=0`

Trường hợp `1`

`5x-2=0`

`=> 5x=0+2`

`=> 5x=2`

`=> x=2:5`

`=> x=2/5`

Trường hợp `2`

`-10/x+8=0`

`=> -10/x=0-8`

`=> -10/x=-8`

`=> x = (-8)/(-10)`

`=> x=4/5`

Vậy `x in {2/5;4/5}`