Question

tìm x biết

a,  ( 2x +3 ) . ( x - 4 ) + ( x - 5) . ( x - 2 )= ( 3x - 5 ) . ( x - 4 )

Answer 1

2x² - 8x + 3x - 12 + x² - 2x - 5x + 10 = 3x² - 12x - 5x + 20

2x² + x² - 3x² - 8x + 3x - 2x - 5x + 12x + 5x = 20 - 10 +12

5x = 22

x = 4,4

Answer 2

a/ \(\left(2x+3\right)\left(x-4\right)+\left(x-5\right)\left(x-2\right)=\left(3x-5\right)\left(x-4\right)\)

<=> \(\left(2x-3\right)\left(x-4\right)+\left(x-5\right)\left(x-2\right)-\left(3x-5\right)\left(x-4\right)=0\)

<=> \(2x^2-8x-3x+12+x^2-2x-5x+10-\left(3x^2-12x-5x+20\right)=0\)

<=> \(2x^2-11x+12+x^2-7x+10-3x^2+17x-20=0\)

<=> \(2-x=0\)

<=> \(x=2\)

Answer 3

x = 2 bạn nha

Answer 4

\(x=2\)

Answer 5

Đáp án: X= 2

Answer 6

            Bài làm :

Ta có :

 \(\left(2x+3\right)\left(x-4\right)+\left(x-5\right)\left(x-2\right)=\left(3x-5\right)\left(x-4\right)\)

 \(\Leftrightarrow\left(2x-3\right)\left(x-4\right)+\left(x-5\right)\left(x-2\right)-\left(3x-5\right)\left(x-4\right)=0\)

 \(\Leftrightarrow2x^2-8x-3x+12+x^2-2x-5x+10-\left(3x^2-12x-5x+20\right)=0\)

 \(\Leftrightarrow2x^2-11x+12+x^2-7x+10-3x^2+17x-20=0\)

 \(\Leftrightarrow2-x=0\)

 \(\Leftrightarrow x=2\)

Vậy x=2