Question

Giải phương trình 4( 18- 5x) – 12( 3x – 7) = 15( 2x – 16) – 6(x+ 14)

Answer 1

Ta có: 

4(18 - 5x) - 12(3x - 7) = 15(2x - 16) - 6(x + 14)    

⇔ 4.18 - 4.5x - 12.3x - 12.(-7) = 15.2x - 15.16 - 6x - 6.14    

⇔ 72 - 20x - 36x + 84 = 30x - 240 - 6x - 84    

⇔ 156 - 56x = 24x - 324    

⇔ 56x + 24x = 156 + 324    

⇔ 80x = 480 ⇔ x = 6    

Answer 2

\(4\left(18-5x\right)-12\left(3x-7\right)=15\cdot\left(2x-16\right)-6\left(x+14\right)\)

=>\(72-20x-36x+84=30x-240-6x-84\)

=>-56x+156=24x-324

=>-80x=-324-156=-480

=>x=6

Answer 3

`4(18 - 5x) - 12(3x - 7) = 15(2x - 16) - 6(x + 14)`
`72 - 20x - 36x + 84 = 30x - 240 - 6x - 84`
`72 + 84 - 20x - 36x = 30x - 6x - 240 - 84`
`156 - 56x = 24x - 324`
`156 + 324 = 24x + 56x`

`480 = 80x`

`x = 6`

Answer 4

`4(18-5x)-12(3x-7) = 15(2x-16)-6(x+14)`

`=> 72 - 20x - 36x + 86 = 30x - 240 - 6x - 84`

`=> 156 - 56x = 24x - 324`

`=> 56x + 24x= 324 + 156`

`=> 80x = 480`

`=>x=6`

Vậy: `S={6}`