Question

Giải các phương trình:

a) 3x + 2(x-5)= -x+2

) 3x^{2 -} 2x = 0

c) \(\dfrac{2x}{3}\) + \(\dfrac{x-4}{6}\)= 2 - \(\dfrac{x}{2}\)

d) \(\dfrac{x-2}{x+2}-\dfrac{3}{x-2}=-\dfrac{2\left(x-11\right)}{4-x^2}\)

e) \(\left(x^2+1\right)\left(x^2-4x+4\right)=0\)
Mấy bạn giúp mk với mk chuẩn vị thi 1 tiết rồi nè!!! Bạn nào giải giúp mk, mk cảm mơn bạn í nhiều lém!!!

Answer 1

a) 3x+2(x-5)=-x+2

<=> 3x+2x+x=2+10

<=>6x=12

<=>x=2

b) 3x²-2x=0

<=>x(3x-2)=0

<=>\(\left[{}\begin{matrix}x=0\\3x-2=0\end{matrix}\right.\)

<=>\(\left[{}\begin{matrix}x=0\\x=\dfrac{2}{3}\end{matrix}\right.\)

c) \(\dfrac{2x}{3}\)+\(\dfrac{x-4}{6}\)=2-\(\dfrac{x}{2}\)

<=>\(\dfrac{8x+2x-8}{12}\)=\(\dfrac{24-6x}{12}\)

<=> 8x+2x-8=24-6x

<=>8x+2x+6x=24+8

<=>16x=32

<=>x=2

d) \(\dfrac{x-2}{x+2}\)-\(\dfrac{3}{x-2}\)= -\(\dfrac{2\left(x-11\right)}{4-x^2}\) ( ĐKXĐ: x\(\ne\)\(\pm\)2)

<=> \(\dfrac{\left(x-2\right)^2-3\left(x+2\right)}{x^2-4}\)=\(\dfrac{2\left(x-11\right)}{x^2-4}\)

=> (x-2)²-3(x+2)=2(x-11)

<=> x²-4x+4-3x-6=2x-22

<=> x²-4x-3x-2x=-22-4+6

<=> x-9x+20=0

<=> (x-4)(x-5)=0

<=>\(\left[{}\begin{matrix}x=4\\x=5\end{matrix}\right.\) ( thỏa mãn diều kiện )

d) (x²+1)(x²-4x+4)=0

=> x²-4x+4=0 (x²+1\(\ge\)1 với mọi x)

=>(x-2)² =0

=>x=2