Question

  giải hộ mik vs 

Answer 1

`a)x^2 - 4+x(x-2)=0`

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

`<=>(x-2)[(x+2)+x]=0`

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

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

`<=>x-2=0` hoặc `2x+2=0`

`<=>x=2` hoặc `x=-1`

Vậy `x=-1` hoặc `x=2`

`b)(2x+1)^2 - 4x^2=0`

`<=>[(2x+1)-2x][(2x+1)+2x]=0`

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

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

`<=>4x+1=0`

`<=>4x=-1`

`<=>x=-1/4`

Vậy `x=-1/4`

`c)x^2 - 75x=0`

`<=>x(x-75)=0`

`<=>x=0` hoặc `x-75=0`

`<=>x=0` hoặc `x=75`

Vậy `x=0` hoặc `x=75`

Answer 2

a, \(x^2-4+x\left(x-2\right)=0\Leftrightarrow\left(x-2\right)\left(x+2\right)+x\left(x-2\right)=0\\ \Leftrightarrow\left(x-2\right)\left(x+2+x\right)=0\Leftrightarrow x=2;x=-1\)

b, \(\left(2x+1\right)^2-4x^2=0\Leftrightarrow\left(2x+1\right)^2-\left(2x\right)^2=0\)

\(\Leftrightarrow\left(2x+1-2x\right)\left(2x+1+2x\right)=0\Leftrightarrow4x+1=0\Leftrightarrow x=-\dfrac{1}{4}\)

c, \(x^2-75x=0\Leftrightarrow x\left(x-75\right)=0\Leftrightarrow x=0;x=75\)