Question

Giải phương trình 2( 5x – 8) – 3(4x – 5) = 4 (3x – 4) + 11

Answer 1

Ta có:

\(2 ( 5x -8) - 3(4x-5) = 4 ( 3x -4) + 11\)

\(\Leftrightarrow 2.5x - 2.8 -3.4x-3.(-5) = 4.3x-4.4+11\)

\(\Leftrightarrow 10x -16 - 12x + 15 = 12 - 16+11\)

\(\Leftrightarrow -2x -1 = 12x -5\)

\( \Leftrightarrow \) \(-2x - 1 = 12x -5\)

\(\Leftrightarrow -2x - 12x = -5 + 1\)

\(\Leftrightarrow -14x = -4 \Leftrightarrow x = \dfrac{2}{7}\)

Answer 2

`2(5x-8)-3(4x-5)=4(3x-4)+11`

`=> 10x-16-12x+15=12x-16+11`

`=> (10x-12x)+(-16+15)=12x-(16-11)`

`=>-2x-1=12x-5`

`=>-2x-12x=-5+1`

`=>-14x=-4`

`=>x=2/7`

Vậy:  `S={2/7}`