giải nhanh cho mk nha mn yêu

Đáp án+Giải thích các bước giải:

a) 

$(x-4)^{2}-(x-2)(x+2)=6$

$⇒$ $x^{2}-8x+16-x^{2}+4=6$

$⇒$ $-8x=-14$

$⇒$ $x=\frac{7}{4}$ 

b)

$x(x-3)-2x+6=0$

$⇒x(x-3)-2(x-3)=0$

$⇒(x-3)(x-2)=0$

$⇒$ \(\left[ \begin{array}{l}x-3=0\\x-2=0\end{array} \right.\) 

$⇒$\(\left[ \begin{array}{l}x=3\\x=2\end{array} \right.\) 

c) 

$2x^{2}+3x-5=0$

$⇒$ $2x^{2}-2x+5x-5=0$

$⇒$ $2x(x-1)+5(x-1)=0$

$⇒$ $(x-1)(2x+5)=0$

$⇒$ \(\left[ \begin{array}{l}x-1=0\\2x+5=0\end{array} \right.\) 

$⇒$ \(\left[ \begin{array}{l}x=1\\x=\frac{-5}{2}\end{array} \right.\)

d)

$ (x-1)^{3}-(x+3)(x^{2}-3x+9)+3(x^{2}-4)=2$

$⇒$ $x^{3}-3x^{2}+3x-1-x^{3}-27+3x^{2}-12=2$

$⇒$ $3x-40=2$

$⇒$ $3x=42$

$⇒ x=14$