Question

giúp mình với ạ

 

Answer 1

Lỗi

Answer 2

Answer 3

a)

<=> (2x+1).(3x-2) - (5x-8 ) . (2x+1 ) =0

<=> (2x+1 ) ( 3x-2-5x+8) = 0

<=> (2x+1)(6-2x)=0

<=> 2x + 1 = 0

       6 - 2x = 0

<=>  2x = -1

        2x = 6 

=>  x = -1/2 ; x = 3

b)

<=> (2x)^2 - 1 = (2x+1)(3x-5)

<=> (2x-1 ) ( 2x + 1 ) - (2x+1) ( 3x-5)=0

<=> (2x+1 ) (2x-1-3x+5)=0

=> 

2x + 1 = 0

4 - x =0

=> x = -1/2 ; x = 4

c)

<=> x^2 + 2x+1 = 4x^2 -8x+4

<=>

x^2 + 2x + 1 - 4x^2 + 8x - 4 = 0

<=>

-3x^2 +10x - 3=0

Δ = b^2 - 4ac = \(10^2-4.-3.-3=64\)

\(\sqrt{\Delta}=\sqrt{64}=8>0\)

=> pt có 2 nghiệm pb

\(x_1=\dfrac{-10+8}{-6}=\dfrac{1}{3};x_2=\dfrac{-10-8}{-6}=3\)

Answer 4