.Giải các phương trình sau:
a, 2x-5x+12=0
b, 3x-6+x=9-x
c, 2x-(3-5x)=4(x+3)
d, 11+42-2x=100-9x-22
e, 2x-(3-5x)=4(x+3)
f, x(x+2)=x(x+3)
g,3x(2x-2)=3×2+1
.Nhờ các cao nhân kisuuuu emmm :33
.Giải các phương trình sau:
a, 2x-5x+12=0
b, 3x-6+x=9-x
c, 2x-(3-5x)=4(x+3)
d, 11+42-2x=100-9x-22
e, 2x-(3-5x)=4(x+3)
f, x(x+2)=x(x+3)
g,3x(2x-2)=3×2+1
.Nhờ các cao nhân kisuuuu emmm :33
a) `2x-5x+12=0`
`⇔-3x+12=0`
`⇔-3x=-12`
`⇔x=4`
`⇒` Vậy `S={4}`
b) `3x-6+x=9-x`
`⇔3x+x+x=9+6`
`⇔5x=15`
`⇔x=3`
`⇒` Vậy `S={3}`
c)`2x-(3-5x)=4(x+3)`
`⇔2x-3+5x=4x+12`
`⇔7x-3=4x+12`
`⇔7x-4x=12+3`
`⇔3x=15`
`⇔x=5`
`⇒` Vậy `S={5}`
d)`11+42-2x=100-9x-22`
`⇔53-2x=78-9x`
`⇔-2x+9x=78-53`
`⇔7x=25`
`⇔x=25/7`
`⇒` Vậy `S={25/7}`
e) `2x-(3-5x)=4(x+3)`
`⇔2x-3+5x=4x+12`
`⇔7x-3=4x+12`
`⇔7x-4x=12+3`
`⇔3x=15`
`⇔x=5`
`⇒` Vậy `S={5}`
f) `x(x+2)=x(x+3)`
`⇔x^2+2x=x^2+3x`
`⇔2x=3x`
`⇔2x-3x=0`
`⇔-x=0`
`⇔x=0`
`⇒` Vậy `S={0}`
g) `3x(2x-2)=3×2+1`
`⇔6x^2-6x=3x^2+1`
`⇔6x^2-6x-3x^2-1=0`
`⇔3x^2-6x-1=0`
`⇒`Vậy `x∈∅`
$g)3x(2x-2)=3x^2+1$
$\to 6x^2-6x-3x^2-1=0$
$\to 3x^2-6x-1=0$
$\to$ vô nghiệm