giải giúp mik ạ pls

`a)2x+6=0`

`⇔2x=-6`

`⇔x=-3`

Vậy `S={-3}`

`b)4x+20=0`

`⇔4x=-20`

`⇔x=-5`

Vậy `S={-5}`

`c)2(x+1)=5x-7`

`⇔2x+2=5x-7`

`⇔2x-5x=-7-2`

`⇔-3x=-9`

`⇔x=3`

Vậy `S={3}`

`d)2x-3=0`

`⇔2x=3`

`⇔x=3/2`

Vậy `S={3/2}`

`e)3x-1=x+3`

`⇔2x=4`

`⇔x=2`

Vậy `S={2}`

`f)15-7x=9-3x`

`⇔-7x+3x=9-15`

`⇔-4x=-6`

`⇔x=3/2`

Vậy `S={3/2}`

`g)x-3=18`

`⇔x=21`

Vậy `S={21}`

`h)2x+1=15-5x`

`⇔2x+5x=15-1`

`⇔7x=14`

`⇔x=2`

Vậy `S={2}`

`i)3x-2=2x+5`

`⇔3x-2x=5+2`

`⇔x=7`

Vậy `S={7}`

`k)-4x+8=0`

`⇔-4x=-8`

`⇔x=2`

Vậy `S={2}`

`l)2x+3=0`

`⇔2x=-3`

`⇔x=-3/2`

Vậy `S={-3/2}`

`m)4x+5=3x`

`⇔4x-3x=0-5`

`⇔x=-5`

Vậy `S={-5}`