Tìm x : (2x + 3) ( x – 4) + (x-5) (x-2) = (3x – 5) (x – 4 ) 20/08/2021 Bởi Skylar Tìm x : (2x + 3) ( x – 4) + (x-5) (x-2) = (3x – 5) (x – 4 )
Đáp án: Giải thích các bước giải: `(2x + 3) ( x – 4) + (x-5) (x-2) = (3x – 5) (x – 4 )` `<=>(2x+3)(x-4)-(3x-5)(x-4)+(x-5)(x-2)=0` `<=>(x-4)(-x+8)+(x-5)(x-2)=0` `<=>-x^2+12x-32+x^2-7x+10=0` `<=>5x-22=0` `=>x=22/5` @kinh0908 Bình luận
Đáp án: $\text{( 2x + 3 )( x – 4 ) + ( x – 5 )( x – 2 ) = ( 3x – 5 )( x – 4 )}$ $\text{ ⇒ ( 2x + 3 )( x – 4 ) + ( x – 5 )( x – 2 ) – ( 3x – 5 )( x – 4 ) = 0}$ $\text{ ⇒ ( x – 4 )( 8 – x ) + ( x – 5 )( x – 2 ) = 0}$ $\text{ ⇒ 8x – 32 – $x^2$ + 4x + $x^2$ – 5x -2x + 10 = 0}$ $\text{ ⇒ 5x = 22}$ $\text{ ⇒ x = $\dfrac{22}{5}$ }$ Bình luận
Đáp án:
Giải thích các bước giải:
`(2x + 3) ( x – 4) + (x-5) (x-2) = (3x – 5) (x – 4 )`
`<=>(2x+3)(x-4)-(3x-5)(x-4)+(x-5)(x-2)=0`
`<=>(x-4)(-x+8)+(x-5)(x-2)=0`
`<=>-x^2+12x-32+x^2-7x+10=0`
`<=>5x-22=0`
`=>x=22/5`
@kinh0908
Đáp án:
$\text{( 2x + 3 )( x – 4 ) + ( x – 5 )( x – 2 ) = ( 3x – 5 )( x – 4 )}$
$\text{ ⇒ ( 2x + 3 )( x – 4 ) + ( x – 5 )( x – 2 ) – ( 3x – 5 )( x – 4 ) = 0}$
$\text{ ⇒ ( x – 4 )( 8 – x ) + ( x – 5 )( x – 2 ) = 0}$
$\text{ ⇒ 8x – 32 – $x^2$ + 4x + $x^2$ – 5x -2x + 10 = 0}$
$\text{ ⇒ 5x = 22}$ $\text{ ⇒ x = $\dfrac{22}{5}$ }$