Question

4x^2+4x+1=0

Answer 1

=>(2x+1)^2=0

=>2x+1=0

=>x=-1/2

Answer 2

`@` `\text {Ans}`

`\downarrow`

`4x^2+4x+1=0`

`<=> 4x^2 + 2x + 2x + 1 =0`

`<=> (4x^2 + 2x) + (2x+1) = 0`

`<=> 2x(2x+1) + (2x+1)=0`

`<=> (2x+1)(2x+1)=0`

`<=> (2x+1)^2 = 0`

`<=> 2x+1=0`

`<=> 2x=-1`

`<=> x=-1 \div 2`

`<=> x=-1/2`

Vậy, `x \in {-1/2}.`